During several recent conversations, people have told me that they've stopped checking their phones in the morning. Not because nothing was happening, but because everything was. They described the feeling as standing under a waterfall of perpetual bad news.

This experience is far from an isolated one. According to Reuters Institute's 2025 Digital News Report, 69% of Canadians at least occasionally avoid the news now.

Globally, 40% report they at least sometimes or often do the same, the highest figure ever recorded. People shared consistent reasons for this: the news put them in a bad mood, they felt overwhelmed and powerless to act.

As a researcher in developmental psychology, focusing on social development and psychological well-being, I argue that news fatigue is not laziness, weakness or a generational decline in civic interest. It's the predictable response of a human brain meeting an environment it was never designed to navigate.

Wired for bad news

Long before smartphones or even the printing press, our cognitive architecture was shaped by a single problem: stay alive long enough to reproduce. Our ancestors whose attention drifted past the rustle in the grass left fewer descendants than those who froze, looked and listened.

The brain that paid attention to threats was the brain that survived.

This is the foundation of what psychologists call the negativity bias, one of the most replicated findings in cognitive science. Across decades of research, the human mind has been shown to weigh negative information more heavily than positive, attend to it faster and remember it longer.

A predator nearby mattered more than a beautiful sunset. The cost of missing a real threat was death, while the cost of overreacting was a few minutes of wasted vigilance. The asymmetry made this bias adaptive.

Here is the problem: the human brain has not changed since then. We are the same species as we were thousands of years ago. What's changed is the size of the world it's asked to scan for threats.

Scanning the whole world

For most of human history, the threats our nervous system processed were local. A neighbouring tribe. A drought. The illness of a child we personally knew. Information about distant places would barely arrive, and if it did, it was mainly irrelevant.

In 2026, the same neurological system is being asked to absorb a war in one region, a financial shock in another, a climate disaster in a third and a violent crime in a fourth, all before lunchtime.

A study published in the scientific journal Nature Human Behaviour examined more than 105,000 real news headlines viewed nearly six million times. Each additional negative word increased click-through rates, while positive words had the opposite effect.

Recent studies suggest people around the world demonstrate measurably stronger physiological responses to negative news than to positive news. The body is reacting before the mind has decided whether the threat is relevant.

Some researchers have introduced a clinical framework for what happens in this instance called Problematic News Consumption (PNC) — a pattern of news engagement that results in preoccupation, dysregulation and disruption to daily functioning. In their 2022 study, the researchers found that 17% of American adults qualified as having severe levels of PNC. Among that group, 61% reported feeling unwell quite a bit or very much, compared with 6% of those who didn't.

For minority populations, news fatigue may be even more consequential.

Repeatedly witnessing harm directed at our own groups, even when we're not the immediate target, can have a significant psychological impact on people from the same group affiliation. For racialized communities, such as immigrants, the cognitive load could be even heavier, and the option to simply stop watching is much harder to exercise when the news is about their country of origin.

Looking away is not the fix

What's the solution to news fatigue? Well, it's not avoidance. A democracy depends on informed citizens.

Many adults already cite the spread of misleading information as a major source of stress. Withdrawing from accurate, trustworthy information only deepens the problem. We're wired to pay more attention to bad news, and that kind of content will find its way to us one way or another.

The fix is to manage the consumption and the sources.

Several approaches can help manage news fatigue and protect mental health. Containing news consumption to defined windows of time reduces the sense of being overwhelmed. Choosing depth over volume also matters: one carefully reported long-form article will inform you better than bursts of random, unreliable and emotionally loaded posts on Instagram.

There is also value in distinguishing between information and action — research on perceived control and stress consistently shows that the gap between awareness and agency is one of the strongest predictors of psychological distress. Identifying what you can actually do about what you read in the news, however small, regulates that response.

Finally, be wary of "rage bait" — intentionally provocative messages or content designed to boost engagement on social media platforms by eliciting negative reactions. Recognizing that certain content creators want to provoke rather than reflect reality creates useful cognitive distance.

The news will not become less "heavy." But our relationship with it can become more deliberate. Our brains were not built for this scale of input. They were, however, built to learn to adapt.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Around 1 in 5 Americans say they've seen a ghost. I'm not one of them, and I probably never will be. I blame my brain.

Let me explain. No one can say definitively that ghosts exist, but many people believe they do. Roughly three-quarters of Americans believe in some form of paranormal activity — not only ghosts, but psychic abilities, precognitive dreams, mediums and anything else that conventional explanations can't account for.

As a psychology professor, I often think about the subjectivity people use when interpreting experiences. I wonder, then, if there are perfectly ordinary explanations for seemingly extraordinary experiences. Maybe a perfect storm of everyday factors can converge and trigger the sensation of a paranormal experience.

In my new book, "Science of the Supernatural," I explore the idea that the human brain might be creating an experience of the supernatural by misinterpreting the external world. Here are three factors that might trick your brain into creating a fake ghost:

Haunted factor #1: Environmental stimuli

Anyone who's ever watched a ghost hunting show has seen the paranormal investigator mutter something like "The EMF's going crazy" when there's purported supernatural activity afoot. Electromagnetic fields, or EMFs, are invisible areas of energy created by electrically charged particles.

At present, there is no direct evidence that humans can consciously sense EMF the same way we can touch, see or hear things in our environment. But with a handheld device purchased at a local hardware store, you can measure them anywhere. An EMF detector picks up electrical or magnetic activity, whether human-made or otherworldly. But do EMF fluctuations relate to paranormal activity?

The scientific method might help answer this question. In one study, conducted in the South Street vaults underneath Edinburgh, Scotland, EMFs fluctuated more in areas with a history of ghostly happenings. Another study found greater variability of EMFs in the more "haunted" areas of Hampton Court Palace in England.

People might unknowingly be detecting changes in environmental stimuli, like electromagnetic fields. The question then becomes: Did the ghost cause the EMF, or did the EMF cause the ghost?

To date, only one research group has attempted to experimentally manipulate environmental factors, including complex EMF, and measure subsequent perceptions of the paranormal.

Participants did report many peculiarities, ranging from feeling dizzy to feeling like they were detached from their bodies and even sensing a presence — but these experiences didn't correspond to how the researchers varied environmental conditions, like EMF intensity. Interestingly, the people who described anomalous experiences were the same people who believed more strongly in the paranormal.

Do environmental factors like EMF lead to perceptions of the paranormal? On the one hand, there is a correlation between reportedly haunted places and EMF variability. And there are some indications that humans can detect magnetism. On the other hand, experimental manipulation of EMF did not relate to weird perceptions in a lab setting.

I think we need to look into other haunted factors.

Haunted factor #2: Neurological mix-ups

By applying a small electrical current to the side of the head, usually to evaluate a patient for a clinical procedure, researchers have observed some strange effects. One case study described a patient who experienced an "illusory shadow figure" that was mimicking, and even interfering, with their movements. Other people have reported out-of-body experiences.

Experimental evidence suggests that this brain area, the temporoparietal junction, is probably crucial for the feeling of embodiment — that you inhabit your own body. Disrupting this brain area seems to trigger a sensation of disembodiment.

Neuroscientists aren't completely sure how the sense of embodiment is built in the brain. The brain probably integrates bodily senses, like balance and position, with other internal processes, like a sense of self and agency. When this integration is altered, a person will experience very strange sensations.

Sometimes, misinterpretation of sensations from the body can happen during sleep, when your brain shuts out the external world. During rapid eye movement, or REM, sleep, when most vivid dreams occur, the brain sends messages that prevent movement of skeletal muscles. This inhibition causes complete paralysis during REM sleep. It is a neurological safeguard; without it, you would be likely to act out your dreams.

Some people, though, wake up during REM sleep and find that they cannot move. They may simultaneously experience rich hallucinations — the remnants of their dream. This experience passes quickly. But in that moment of sleep paralysis, the neural signals that control skeletal muscle movement are inhibited, resulting in a mismatch of feedback from the body to the brain. Most people respond to the missing sensory information with fear, which makes them more likely to experience the sights and sounds from their dreams as reality.

Haunted factor #3: Personality traits

Living through a paranormal encounter requires that a person label their experience as such. If a believer were exposed to fluctuating EMFs, for example, they might be quick to categorize the strange sensation as paranormal. A skeptic might note they felt weird or off, but probably not point to a paranormal explanation.

There's a growing body of research that suggests people with certain personality traits are more likely to believe in the paranormal.

For instance, some people are hyperaware of unconscious perceptions and ideas, which then permeate their consciousness. Often, these traits are associated with magical thinking, distorted or unusual thoughts, disorganized behavior and, sometimes, trouble forming close relationships.

Psychologists refer to this set of traits as schizotypy. They're related to schizophrenia, although being high in schizotypy doesn't mean you will be diagnosed with the disorder of schizophrenia. People with high levels of schizotypy are more likely to believe in the paranormal. They're also more likely to experience disembodiment and spontaneous sensory perceptions and have trouble discriminating between self and others.

All of these traits relate to the function of the temporoparietal junction — the brain area that helps you know you're located within your own body.

When haunted factors add up to a ghost

While I cannot say for sure whether ghosts exist, I can propose a plausible explanation for why some people might be more prone to apparent paranormal experiences than others.

Consider a person who believes in paranormal phenomena who experiences a natural change in electromagnetic fields or an episode of sleep paralysis. Those experiences induce unusual sensations that this person cannot explain. Searching for meaning in ambiguity, this person distorts their distinction between internally and externally generated sensations. They settle on the only explanation that makes sense to them — that this strange feeling they experienced was a ghost.

My guess is that belief in the paranormal is the glue that holds the haunted factors together to create the (mis)perception of a ghost.

One experiment asked participants to walk through a disused theater in Decatur, Illinois. Some were told that the theater was haunted, and some were not. Several participants noted weird sensations that they attributed to paranormal activity — but only those who believed that the theater was haunted reported these sensations.

Belief alone might not create a ghost, but belief combined with at least one haunted factor — environmental stimuli, neurological hiccups or psychological conditions — might be enough to make a ghost real.

This becomes a chicken-or-the-egg riddle — or in this case, the ghost or the EMF. Someone who is more likely to be sensitive to environmental factors or who experiences sleep paralysis might create belief from their experiences. When someone cannot explain these experiences with any "natural" explanation, a supernatural explanation might be the only one that makes sense.

I've never noticed EMF. I've never experienced sleep paralysis. I'm pretty sure I don't have personality traits like schizotypy. I don't believe in the paranormal. And I don't think I'll ever see a ghost.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Images of faces generated by artificial intelligence (AI) are so realistic that even "super recognizers" — an elite group with exceptionally strong facial processing abilities — are no better than chance at detecting fake faces.

People with typical recognition capabilities are worse than chance: more often than not, they think AI-generated faces are real.

That's according to research published Nov. 12 in the journal Royal Society Open Science. However, the study also found that receiving just five minutes of training on common AI rendering errors greatly improves individuals' ability to spot the fakes.

"I think it was encouraging that our kind of quite short training procedure increased performance in both groups quite a lot," lead study author Katie Gray, an associate professor in psychology at the University of Reading in the U.K., told Live Science.

Surprisingly, the training increased accuracy by similar amounts in super recognizers and typical recognizers, Gray said. Because super recognizers are better at spotting fake faces at baseline, this suggests that they are relying on another set of clues, not simply rendering errors, to identify fake faces.

Gray hopes that scientists will be able to harness super recognizers' enhanced detection skills to better spot AI-generated images in the future.

"To best detect synthetic faces, it may be possible to use AI detection algorithms with a human-in-the-loop approach — where that human is a trained SR [super recognizer]," the authors wrote in the study.

Detecting deepfakes

In recent years, there has been an onslaught of AI-generated images online. Deepfake faces are created using a two-stage AI algorithm called generative adversarial networks. First, a fake image is generated based on real-world images, and the resulting image is then scrutinized by a discriminator that determines whether it is real or fake. With iteration, the fake images become realistic enough to get past the discriminator.

These algorithms have now improved to such an extent that individuals are often duped into thinking fake faces are more "real" than real faces — a phenomenon known as "hyperrealism."

As a result, researchers are now trying to design training regiments that can improve individuals' abilities to detect AI faces. These trainings point out common rendering errors in AI-generated faces, such as the face having a middle tooth, an odd-looking hairline or unnatural-looking skin texture. They also highlight that fake faces tend to be more proportional than real ones.

In theory, so-called super recognizers should be better at spotting fakes than the average person. These super recognizers are individuals who excel in facial perception and recognition tasks, in which they might be shown two photographs of unfamiliar individuals and asked to identify if they are the same person or not. But to date, few studies have examined super recognizers' abilities to detect fake faces, and whether training can improve their performance.

To fill this gap, Gray and her team ran a series of online experiments comparing the performance of a group of super recognizers to typical recognizers. The super recognizers were recruited from the Greenwich Face and Voice Recognition Laboratory volunteer database; they had performed in the top 2% of individuals in tasks where they were shown unfamiliar faces and had to remember them.

In the first experiment, an image of a face appeared onscreen and was either real or computer-generated. Participants had 10 seconds to decide if the face was real or not. Super recognizers performed no better than if they had randomly guessed, spotting only 41% of AI faces. Typical recognizers correctly identified only about 30% of fakes.

Each cohort also differed in how often they thought real faces were fake. This occurred in 39% of cases for super recognizers and in around 46% for typical recognizers.

The next experiment was identical, but included a new set of participants who received a five-minute training session in which they were shown examples of errors in AI-generated faces. They were then tested on 10 faces and provided with real-time feedback on their accuracy at detecting fakes. The final stage of the training involved a recap of rendering errors to look out for. The participants then repeated the original task from the first experiment.

Training greatly improved detection accuracy, with super recognizers spotting 64% of fake faces and typical recognizers noticing 51%. The rate that each group inaccurately called real faces fake was about the same as the first experiment, with super recognizers and typical recognizers rating real faces as "not real" in 37% and 49% of cases, respectively.

Trained participants tended to take longer to scrutinize the images than the untrained participants had — typical recognizers slowed by about 1.9 seconds and super recognizers did by 1.2 seconds. Gray said this is a key message to anyone who is trying to determine if a face they see is real or fake: slow down and really inspect the features.

It is worth noting, however, that the test was conducted immediately after participants completed the training, so it is unclear how long the effect lasts.

"The training cannot be considered a lasting, effective intervention, since it was not re-tested," Meike Ramon, a professor of applied data science and expert in face processing at the Bern University of Applied Sciences in Switzerland, wrote in a review of the study conducted before it went to print.

And since separate participants were used in the two experiments, we cannot be sure how much training improves an individual's detection skills, Ramon added. That would require testing the same set of people twice, before and after training.

Climate change is real. It’s happening. Now. Here. Wherever you are.

Recognizing that climate change is immediate, close, and affecting people's way of life is one of the key messages we need to communicate to spur them to act.

Despite efforts from bad faith actors trying to spread misinformation and disinformation, the public overwhelmingly accepts that much more urgently needs to be done to address climate change. But in order to meaningfully limit warming, we need to enact policies that will alter the lives of billions of people.

And this needs to begin with individual action — getting people to care enough to alter their behavior around climate change. If enough people realize that climate change will affect them personally and start engaging on an individual level, we might see a turn in the political tide that ends with the real, large-scale changes needed to limit rising global temperatures.

In the social satire fiction film Don't Look Up, two astronomers are tasked with telling the world that a comet twice the size of the dinosaur-ending meteor was imminently going to hit Earth. In a tense exchange, a morning talk show host seeks to minimize the risk:

Kate Dibiasky: I'm sorry... Are we not being clear? We're trying to tell you that the entire planet is about to be destroyed.

Brie Evantee: Well it's uh, you know, it's something we do around here. We just keep the bad news light.

The film was widely praised for satirizing responses to the global climate crisis, including from climate scientist Peter Kalmus. We wanted to find out if there are ways we can present information about climate change that lifts people into action, rather than keeping the "bad news" at arms length.

Getting people to act

We recruited more than 3,000 participants across six countries to see what would make them more or less motivated to help climate causes. Pro-environmental actions are often costly — incurring financial, time and physical effort. We wanted to find out how people weigh up these costs with the benefits for the planet and whether we can use psychology to spur the meaningful behavior shifts needed.

We did this by creating a physically demanding task that earned donations to a climate action charity, and compared that with a non-environmental, food cause: ending world hunger. Before doing the task, some participants saw different messages and pictures designed by psychology experts to try and boost their motivation to take climate action. One group of participants didn't see any of these messages to give us a baseline measure.

Interestingly, the participants who didn't see any of the pro-environment messages were more likely to make an effort for the food cause than the climate. This finding was relatively consistent across the six countries we worked with: Bulgaria, Greece, Nigeria, Sweden, the U.K., and the U.S..

We then tested which of the messages promoted pro-climate behaviors.

What worked well:

Psychological distance: Climate change was presented as an immediate, local threat, and participants reflected on how it affects them personally.

System justification: Climate change was presented as a threat to participants' way of life and encouraged pro-environmental behaviour as patriotic.

What didn't work so well:

Scientific consensus: Participants saw a message and graphic emphasizing that 99% of climate scientists agree climate change is real and caused by humans.

Binding moral foundations: Participants read a message invoking national pride, loyalty, and authority to support clean energy and climate action.

It's personal

The findings confirm some things that we know to be true about human behavior. It's the same reason why people have a greater connection to news that is local to their area, or to their interests. When it's personal, when it's close, when it affects our usual way of life, it lands.

To better motivate people to take climate action now, our new study suggests that closing the psychological distance between individuals and the generalized, vague threat of climate change affecting the world at large is among the most motivating factors we need to employ.

When rising water levels affect another country, the uncomfortable truth is that our brains are wired to take the threat less seriously because it affects another group of people that we aren't as well connected to. However, if it affects people or places that we know and love, it makes it personal and closer to home.

People are also motivated to protect their status quo and current way of life. Sometimes this can be a barrier against changing our behavior. But we found flipping this psychology can motivate action. When rising water levels increase the risk that our property is going to be flooded — because events that were previously likely to happen once in 100 years are increasingly common — to protect our way of life requires us to take action, rather than do nothing.

When the once in 100-year flood has happened for the third time in as many years and water is pouring under the door, it is personal and it's at home.

We know addressing climate change will require systemic change from governments and business. But we need to start somewhere, and getting people to see the changes happening around them may just be a small step that leads to major shifts. Our homes are all at risk if we don't try.

Opinion on Live Science gives you insight on the most important issues in science that affect you and the world around you today, written by experts and leading scientists in their field.

Chimpanzees use a variant of the "scientific method" — discarding prior beliefs if convincing new evidence comes along to change their minds, new research suggests.

When tasked with finding a tasty treat hidden in one of two boxes, chimps (Pan troglodytes) evaluated several strands of evidence. And they switched their choices if new, contradictory evidence emerged, the study found.

The findings are evidence that chimps use metacognition, or thinking about thinking, to weigh evidence and plan accordingly.

"When they revise their beliefs, they actually explicitly represent the evidence they have, and they weigh different types of evidences," study co-author Jan Engelmann, a comparative psychologist at the University of California, Berkeley, told Live Science.

Humans routinely use metacognition to weigh different strands of evidence and create plans based on the information available. We also update our strategies when our plans don't go as we hoped.

Scientists have long known that primate species can assess evidence. Chimpanzees look for food by tracking crumb trails and will seek out more information if existing evidence isn't clear. But we didn't know if chimps could perform a key metacognitive task: changing beliefs in response to new evidence. Engelmann's team used several behavioral tests to answer this question, all of which involved food rewards placed in one of two boxes. In the first two tests, the chimps were trained to choose one of the boxes to receive the food inside and presented with two pieces of conflicting evidence as to which box contained the food. The chimps were presented with one piece of evidence, chose a box, and then given the other piece of evidence and allowed to choose again.

The evidence varied in strength. In one "strong" evidence condition, the team cut a window into the side of one of the boxes, which enabled the chimp to see the food inside. To give "weak" evidence, the researchers shook the other box to indicate something was inside it. The apes were far more likely to change their minds when the researchers presented strong evidence after their initial choice than when they presented weak evidence.

But these results didn't tell the researchers why the chimps changed their minds.

"You can revise your beliefs without really thinking about the evidence," Engelmann said.

The researchers arranged a third test in which they showed the chimps three boxes. One box had strong evidence that it contained food, the second had weak evidence, and the third had none. Before they could pick, the "strong evidence box" was removed. Left with a binary choice, the apes consistently picked the weak evidence over no evidence at all. This showed that the chimps considered both the strong and weak evidence in their decision-making, rather than just considering the strong evidence without reflecting on the other options available, Engelmann said.

In the final experiments, the researchers tested two further metacognitive abilities in the apes. This time, after the researchers presented the weak and strong evidence for the two boxes, they offered another piece of weak evidence. This was either the same weak evidence as before — the researchers rattling the box to show something was inside it — or a new piece of evidence: the sound of a researcher dropping a second piece of food into the box.

The apes were more likely to change their mind and choose that box when they heard two different pieces of evidence, rather than the same piece of evidence twice, showing that they considered how various pieces of evidence combined to strengthen an argument.

In the final test, the researchers again added extra evidence for the apes to consider after they had made their first choice. This time, the new evidence undermined the first piece of evidence; for example, by showing the chimps a pebble inside one of the boxes that could have made the rattling sound they had previously heard. The apes consistently responded to this contradictory evidence by changing their mind.

To Cathal O'Madagain, a cognitive scientist at the University of Mohammad VI Polytechnic in Morocco who was not involved with the study, this final experiment was key to proving the apes' metacognitive ability. "Study five is showing a kind of rationality that studies one and two are not showing," he told Live Science. Test five showed that the original and contradictory evidence were linked, and the apes' changed minds reflected that they were "keeping track" of the original information, he added.

O'Madagain said that the paper, in concert with other, earlier studies of chimpanzee rationality, shows that chimps passed what he called the "high bar" of rationality, making choices based on evidence and keeping that evidence in mind as their world changed. The new findings suggest that discoveries about other animals' minds aren't limited by their shortcomings, but by our own, O'Madagain said "The biggest constraint on our understanding of other animals' intelligence is our ability to come up with appropriate ways to check it."

Engelmann and his team now plan to extend their experiments to other non-human primates to see if they can pass this rationality test, too.

Happiness is known to correlate with better health. But now, researchers have identified a happiness threshold above which people are less likely to die prematurely of chronic diseases like cancer, diabetes and heart disease.

By comparing data from 123 countries over 15 years, researchers pinpointed a threshold at which mortality declined as well-being increased. Every incremental improvement in well-being above this level was tied to a corresponding drop in the risk of death.

Cancer, heart disease, asthma and other chronic diseases accounted for 75% of non-pandemic related deaths in 2021, according to the World Health Organization (WHO). In the U.S., they're collectively the leading causes of illness, disability and death.

Overall chronic disease mortality decreased in the U.S. between 2010 and 2019, but its prevalence increased among Americans ages 20 to 45 years old, according to a study published in The Lancet earlier this year.

A tipping point

Although previous research assumed a positive association between happiness and health, the goal for this new study, which was published Monday (Oct. 20) in the journal Frontiers of Medicine, was to identify a tipping point at which a higher level of well-being would be associated with measurable health improvements — namely, a reduction in premature deaths due to chronic disease.

To do that, the researchers looked at yearly happiness scores in 123 countries, which they averaged to estimate the national level of subjective well-being.

Related: Can faking a smile make you feel happier?

Respondents from the happiness datasets used in the study were asked to visualize a ladder, with the top representing the best possible life and the bottom the worst. They were then asked to rate their present satisfaction and assess their future on a scale of 0 (bottom of the ladder) to 10 (top of the ladder). This tool, known as the Cantril's life ladder scale, is a well-known social science tool used to gauge life satisfaction.

Researchers then compared this measure of national well-being with chronic disease mortality rates in each country over a period of 15 years (2006 to 2021).

The study identified a happiness threshold of 2.7 on the life ladder scale. Above that threshold, every 1% increase in happiness was associated with a 0.43% decrease in premature deaths from chronic disease.

The average life ladder score among the 123 countries studied was 5.45 between 2006 and 2021, so a 2.7 score suggests participants were "barely coping," study co-author Iulia Iuga, a professor at 1 Decembrie 1918 University in Romania said in a statement.

Health effects of subjective well-being

Although the new study doesn't establish a strict cause-and-effect relationship, scientists have identified several ways well-being could have health benefits.

For one, happiness could reduce the impact of stress, which is strongly associated with the development of many chronic diseases.

"We find that positive emotion can serve as a buffer for stressful experiences," said John Hunter, an assistant professor of psychology at Chapman University in California who was not involved in the research."When you have more positive emotion, you have less stress reactivity, which means that when a stressor hits you, you react less severely," Hunter said. "Your heart rate spikes a little bit less; your blood pressure spikes a little bit less. The way that you release stress hormones also changes."

In addition, people with higher levels of positive emotion often maintain stronger relationships and healthier habits.

"People who are optimistic, people who are happy, people who have a more dynamic, happy social life, people who have a strong sense of life purpose [...] tend to be more proactive about their health," said Dr. Alan Rozanski, a cardiologist and professor of medicine at the Icahn School of Medicine at Mount Sinai who was not involved in the study. "They tend to exercise more. They tend to have better diets. They tend to sleep better."

A useful tool for policymakers

The new study could help policymakers think of happiness as a "public health resource" and use it alongside other key factors to mitigate the impact of chronic diseases on their population, the study authors said in a statement.

Policymakers should aim to push their population’s average well-being above the Cantril threshold while addressing trends and environmental conditions that can worsen chronic conditions, such as obesity, alcohol consumption and pollution, Iuga told Live Science in an email.

In places where well-being is lower, focusing on financing healthcare and improving governance is necessary to unlock the positive health effects of increased happiness, Iuga added.

Because the well-being data used in this study is self-reported, it could be subject to measurement errors, the study noted. In addition, various cultures might assess their level of subjective happiness differently.

The life ladder scale used in this study could also be interpreted as a measure of status rather than emotional happiness, Hunter said. So the question may be capturing people’s economic state and living conditions, rather than their emotional state, he said.

People who view society as competitive are more likely to admire antagonistic leaders, a new study finds. Meanwhile, those who see society as cooperative are more likely to call those same leaders ineffective.

Researchers surveyed more than 2,000 participants about coercive behaviors — such as making threats or blaming problems on others — and observed that reactions to these behaviors weren't universal, but instead depend on the observer's worldview.

These results suggest that people who view the world as dog-eat-dog would evaluate a leader who behaves antagonistically as more competent and more effective than people who believe members of a society are symbiotic, helping one another.

"Our work highlights that eye-of-the-beholder effects are meaningful," study co-author Christine Nguyen, a doctoral student at Columbia Business School in New York, told Live Science in an email. The study's results were published in the APA's Journal of Personality and Social Psychology on July 14.

Worldview impacts perceptions of leadership

Nguyen and co-author Daniel Ames, a social psychologist at Columbia Business School, hypothesized that people who view society as competitive are more likely to value antagonistic leaders. To test the idea, they surveyed 2,065 people from the United States, asking them to participate in seven different evaluations. In the study, antagonistic behavior was defined to include mean, tough and intimidating actions, as opposed to friendly and agreeable behaviors.

Related: AI is just as overconfident and biased as humans can be, study shows

The surveys each included 10 questions to determine the participants' worldviews, asking about the extent to which they agreed with various statements. One example was: "My knowledge and experience tell me that the social world we live in is basically a competitive 'jungle' in which the fittest survive and succeed, in which power, wealth, and winning are everything, and might is right." Participants responded on a seven-point scale, from "strongly disagree" to "strongly agree."

Another survey had participants rate the impact of behaviors, such as making threats, blaming others or acting abrasively, from "would greatly decrease their ability to get things done" to "would greatly increase their ability to get things done." In another, participants reacted to hypothetical depictions of workplaces managed by people with varying degrees of antagonistic behavior.

Finally, one survey had participants rate the behaviors of real-world, well-known business leaders, including CEOs such as Apple's Tim Cook and Walt Disney's Bob Iger. Participants rated whether they thought a given CEO used antagonistic behaviors to aid their "rise to the top."

Across all the surveys, people who viewed the world as competitive were more likely to find antagonistic leaders competent. In other words, those with a stronger belief in society having an inherently cutthroat nature were more likely to see antagonistic actions as having a positive impact or being effective. When asked to evaluate CEOs, people with this worldview assumed the leaders used confrontational tactics that helped them succeed in their careers.

People with a competitive worldview were also more likely to report working under antagonistic managers themselves.

"Over time, through processes like employees selectively joining and leaving, antagonistic leaders may find themselves surrounded by a subset of employees with stronger competitive jungle beliefs, who are more tolerant and approving of their behavior," Nguyen said in a statement.

"We're seeing the world differently"

Past research has shown that people's perception of behaviors is partly dependent on factors like their job and location. But "our work is the first to apply this to judgments of leaders through the lens of competitive worldviews," Ames told Live Science in an email. He added that both employees and managers could learn from the study.

"To help people to thrive and find satisfaction in their work means we should understand not only how and why managers behave as they do, but also how and why people perceive managers as they do," he said.

For example, he suggested that leaders should recognize that people evaluate them "not just based on the leader's visible behaviors but also through the lens of those onlookers' own belief systems." While a manager might believe that their leadership style is being evaluated in the vacuum of the workplace, the study places their impact in a broader context, he suggested.

Nguyen did flag that, because all the survey respondents are based in the United States, their results may not be applicable globally. That said, Nguyen and Ames both hope that the work inspires people to reflect on how they view leaders around them, and for leaders to reflect on their perceived impact.

"We hope this research helps people understand that when we disagree about what makes someone competent or admirable, it might be that we're seeing the world differently," Nguyen said.

People with artificial limbs can come to sense their prosthetic as part of their body — and in a new study, scientists showed that lab mice can also experience this same type of "embodiment." The researchers say that the work could inform the design of better artificial limbs for people in the future.

Through this line of research, "we are bringing a toolkit for … neural engineering in mice [and could] discover new ways to control a prosthesis," said senior study author Luc Estebanez, a researcher who studies sensorimotor integration and plasticity at the Université Paris-Saclay.

We all have an internal map of our bodies that helps us track how they're moving, what they're touching and how they're interacting with the environment. Ideally, when someone loses a limb and gains a prosthetic, they incorporate it into this mental map, internalizing it as a part of their body. This sense of ownership and control is gained through a process called "prosthetic embodiment."

However, many people who use prosthetics encounter difficulties with embodiment. Additionally, there are some psychiatric disorders — such as schizophrenia and severe depression — in which people's internal maps grow fuzzy and they lose sense of their bodies, which can contribute to a lack of care for their own bodies and a higher risk of severe accidents.

In the new study, published Thursday (June 5) in the journal PLOS Biology, researchers at the Université Paris-Saclay developed a new model to study limb embodiment using lab mice. This model could enable researchers to study the neuroscience behind embodiment more closely, and maybe even design enhanced prosthetics for those who have lost limbs.

Related: 'You can get the feeling that you are touching another human': New prosthetic device detects temperature

Most studies of prosthetic embodiment feature human subjects and use assessments, like questionnaires, and brain scans. But this approach limits how we can study more granular changes that unfold in the brain during embodiment.

"Embodiment is a multifaceted phenomenon, encompassing neural, behavioural and phenomenological dimensions," said Tamar Makin, a professor of cognitive neuroscience at the University of Cambridge who was not involved in the study. "The latter — the subjective sense of body ownership — is arguably the most critical, and also the most inaccessible in nonverbal species," such as mice, Makin told Live Science in an email.

Prosthetics have been designed to meet the immediate needs of humans first, but that leaves "a blind spot regarding neurotechnologies in mice," said Estebanez. "All the tools are there, but the robotics and the psychology tests that are related to them have never been developed."

So Estebanez and his team wanted to see if lab mice would exhibit similar behaviors to humans in terms of how they internally represent their own bodies. That could open the door to studying how embodiment works in more detail than is possible with human subjects.

To this end, the researchers employed the "rubber-hand illusion," a well-known psychology experiment in which one arm is hidden behind a barrier and a rubber arm is placed at the subject's side, where they can see it. Then, an experimenter runs a brush over both the rubber arm and the subject's real arm at the same time. This creates the illusion that the subject is feeling through the rubber hand — so when the experimenter suddenly raises a hammer to strike the rubber arm, most subjects show a visceral fear reaction, even though they're totally safe.

In the mouse study, the researchers used a rubber paw instead of a hand. By following and quantifying the rodents' pupil movements, they found that the mice reacted in a similar way to humans when the rubber paw was threatened by the rapid approach of an arrow-like object. In short, mice fell for the illusion too.

Interestingly, the mice did not react in the same way when the rubber paw was replaced with a simple block, again replicating what has been seen in human studies. That indicates that the mice don't just need to see the fake paw — it must also look similar to their real paw.

"To really study embodiment, you need to look at mice in a way people don't look at mice," Estebanez argued. "If you take the full consequence of the study, it suggests that mice actually have a very rich cognitive representation of their body, which is super exciting."

The research also suggests that mice could be used to answer deeper biological questions about which parts of the brain actually encode embodiment. Such studies could help those with prosthetics or with disorders that affect embodiment, the researchers say.

The new model is also unique in that it will enable scientists to stimulate the mouse brain in targeted ways, and switch specific brain cells on and off in ways that cannot be performed in humans. They envision that such a model could then be used to design better brain-computer interfaces — devices that link the brain's electrical activity to an external device — which could improve designs for advanced neuroprosthetics.

Makin, however, remains skeptical of how this model can actually be used in the context of neuroprosthetic research.

"I would advise caution in drawing links to neuroprosthetics," she said. "The limb in this study is passive, with no voluntary control or sensorimotor loop. Most of the challenge in neuroprosthetic embodiment arises from the burden of control, which is precisely what this model does not address."

Estebanez noted that, in another project, the team developed a tiny prosthesis for their mice that they can control through a brain-computer interface. "That's where things become interesting," he said. "We would like to probe the level of embodiment we manage to trigger through motor controls and [this mini-prosthesis has now] become part of a toolkit for neuroengineering in mice."

Psychology quiz: What do you know about psychology's most infamous experiments?

When wrestling with a moral dilemma, a person may reach a decision not only by thinking through the problem but also by tuning into physical signals from their body, a new study suggests.

The research found that people who are more in tune with their body signals — such as shifts in their heart rate — tend to make moral decisions that align with the judgments that most other people would make if presented the same scenario. These findings suggest that such internal, physical cues could thus play a role in guiding a person's moral intuition, the study authors said.

"Morality is often viewed as a product of culture and context," Tamami Nakano, a cognitive neuroscientist at the University of Osaka who was not involved in the study, told Live Science in an email. "Showing that bodily signals actively mediate this calibration is both novel and compelling."

In short, the study supports the idea that these bodily reactions form part of a feedback loop that helps guide people in their decision making.

What's more, previous studies have suggested that siding with the majority in a moral dilemma could help take some strain off the brain, and the new study seems to align with that notion, too.

"Recent theories suggest that our brains are designed to minimize physical resource consumption while maintaining survival," study co-author Hackjin Kim, a neuroscientist at Korea University, told Live Science in an email. "One way to do this [conserve energy] is to learn others' expectations to avoid social conflict," Kim suggested. Combining these ideas, Kim and colleagues proposed that people who are better attuned to their bodily feedback signals may use that information to keep their decision-making in line with others' expectations.

Related: People really can communicate with just their eyes, study finds

In their new study, published May 5 in The Journal of Neuroscience, the team tested this hypothesis by presenting participants with moral dilemmas and asking them to choose between two decisions — one "utilitarian," which prioritized minimizing harm for the most people, and one "deontological," which prioritized following established rules and norms.

In a separate test, the researchers asked the participants to focus on their bodies and count their heartbeats over a short interval while the participants' heartbeats were simultaneously recorded with an electrocardiogram.

People who were more accurate at counting their heartbeats also tended to choose the moral decision that most other people chose, the team found. This was true whether more people chose the utilitarian or deontological option for a given moral dilemma.

It may be that cues from a person's body help signal when the person is about to do something that could run up against social norms — a scenario that requires more energy and effort to navigate, the study authors propose. Basically, it's easier to go with the flow than run against the grain.

"The idea is that feeling that anxiety is going to make you notice that you did something to cause that anxiety, and then make you try to avoid doing those things in the future," said Jordan Theriault, a psychologist and biologist at Northeastern University who was not involved in the study. "You feel that feedback from your body, and then you learn not to do that again in the future," he told Live Science. As Theriault describes, you learn over time what others expect of you morally, and your physical reactions form part of the feedback loop that helps guide future decision making.

In the study, participants responded to each dilemma without knowing which of the two options other people chose. They weren't pressured into making a certain decision or conforming to what the rest of the group unknowingly agreed upon, so the results reflect each individuals' moral intuition. Notably, all 104 participants were Korean university students, so it's possible they shared similar cultural and demographic backgrounds as well as similar moral norms.

The team also studied people's brains while at rest to determine how much time they spent in different "brain states" — patterns of brain activity associated with different kinds of tasks. The brain switches back and forth between many different states even when a person isn't doing anything specific.

To track these states, the team used functional magnetic resonance imaging (fMRI), which tracks blood flow as an indirect measure of brain activity. The researchers found that the people who were more aware of their body's signals tended to spend more time in a brain state associated with evaluation and judgment. This particular state was marked by activity in a brain region called the medial prefrontal cortex, which has previously been linked to the process of adjusting choices to meet other people's expectations.

Related: How much of your brain do you need to survive?

These brain scans may further support the idea that people who are more in tune with their bodily signals use those cues to stay aligned with majority opinion. However, because these data were collected separately from the moral-decision tasks, "we still need task-based evidence showing which specific brain regions process body-related signals when people face real moral dilemmas and how these signals influence behavior in real time," Nakano told Live Science. This might involve having people contend with moral dilemmas while in an fMRI scanner.

In future work, Kim plans to investigate how the relationship between moral intuition and awareness of body signals varies among cultures, types of moral dilemmas and individual personality differences. But for now, Kim said, "this research lays a new theoretical framework for understanding cultural and individual differences in moral behavior and predicting norm-following behavior in group or online settings."

Time may fly when you're having fun, but at other times, it seems to crawl along at a glacial pace. For many, time seems to move more slowly while they exercise — you glance at the clock between miles on the treadmill or sets in the weightroom, and you discover that your last half hour of effort was actually only 10 minutes long.

So do people really sense time differently during exercise? And if so, why is that?

At least in experimental studies, people do perceive time as moving more slowly during exercise, whether they're exercising alone or competing against others, according to a study published April 2024 in the journal Brain and Behavior.

Earlier research had shown that exercise can distort our perception of time, making it feel like it's dragging. But it wasn't clear from that work whether the presence of a competitor might distract from the discomfort of exercise and make time feel like it's passing more quickly. So researchers set out to test whether competing against an opponent would shift attention away from internal sensations and, in turn, speed up perceived time.

Related: 'Flow state' uncovered: We finally know what happens in the brain when you're 'in the zone'

They recruited 33 physically active adults —16 women and 17 men — who completed three separate 2.5-mile (4 kilometers) cycling trials in a virtual environment. One was a solo trial, while the others involved biking with a virtual person who was either a noncompetitive cycling buddy or an active competitor in a race.

Before, during and after each trial, researchers asked participants to rate how hard they felt they were working out on a scale of 0 to 10 and to estimate when 30 seconds had passed while the researchers measured the actual time with a stopwatch.

"During exercise, participants said 'stop' at 28.0 seconds. In contrast, before and after exercise, they stopped the clock at 31.4 and 31.6 seconds, respectively," study co-author Stein Menting, now a research associate at Ulster University, told Live Science in an email. "This led us to conclude that time was perceived to run slower during exercise compared to at rest." They observed this effect throughout each trial and across both solo and competitive rounds.

While the virtual competitors didn't affect time perception, they did push participants to cycle faster. When participants were told to race against an on-screen competitor and try to win, they finished in 459 seconds, on average. This was quicker than when they saw the same on-screen person but were only told to go as fast as they could (about 467 seconds), or when they exercised alone (about 470 seconds).

Although participants felt the exercise got harder as they went on, this effort didn't seem to affect their perception of time. This suggests "that it is exercise itself, rather than its intensity, that might distort time perception," Menting said. However, prior research has shown that higher fixed intensities may slow time perception, indicating that the exercise type — self-paced or fixed — may influence this effect, he added.

Additionally, "It's still unclear whether the results are generalisable," study co-author Andrew Edwards, head of the School of Psychology and Life Sciences at Canterbury Christ Church University, said in a statement. The sample size was small, and "while the participants weren't professional cyclists, they were in good physical shape, which isn't true of everybody," he noted.

For athletes, having a distorted sense of time during intense effort may cause them to slow down, potentially limiting performance. Managing how they perceive time could be a key factor in staying on pace. But if the study's findings are generalizable, their implications go beyond elite sports — they could be useful for anyone who exercises, as we often misjudge how much time has passed when we're physically pushing ourselves.

"Setting a timer for very intense exercise would be wise so that we persist exercising for a set amount of time," Philip Gable, a professor of social psychology at the University of Delaware, who was not involved in the study, told Live Science in an email.

Why time seems to slow

The researchers suggested that attention might help explain why time slows. During intense exercise, people shift into a hyper-aware mental state and thus become more conscious of physical discomfort, they suggest. This heightened awareness may increase the number of sensations they perceive in a short time, making it feel longer than it actually is.

But this attention-based mechanism of time distortion is up for debate.

"The authors of the study did not investigate a mechanism," Gable said. "However, the studies run in my lab reveal that attention is not the mechanism of time perception speeding or slowing. It is motivation."

In a series of studies, Gable and his colleagues found that our perception of time can speed up or slow down depending on the type of motivation we feel during a given activity. When people are driven by so-called approach motivation — a desire to move toward something positive — time tends to fly. But when they experience avoidance motivation — the urge to escape something unpleasant — time drags.

"In this current [2024] study, the 'all-out' pace from the participants is likely to be aversive and cause avoidance motivation," Gable said. Because the body can't sustain that level of intensity for long, the participants were motivated to stop cycling, he suggested.

In this aversive state, Gable said, time can feel like it's slowing down. It's the brain's way of discouraging us from continuing something that's physically unsustainable.

According to Gable, the impression that time is slowing down indicates that an exercise regime is causing dread. Based on this, Gable recommends finding "a pace of exercise that is sustainable and doesn't cause too much avoidance — you don't want to hate your exercise!"

This article is for informational purposes only and is not meant to offer medical or fitness advice.

In 1785 English philosopher Jeremy Bentham designed the perfect prison: Cells circle a tower from which an unseen guard can observe any inmate at will. As far as a prisoner knows, at any given time, the guard may be watching — or may not be. Inmates have to assume they're constantly observed and behave accordingly. Welcome to the Panopticon.

Many of us will recognize this feeling of relentless surveillance. Information about who we are, what we do and buy and where we go is increasingly available to completely anonymous third parties. We're expected to present much of our lives to online audiences and, in some social circles, to share our location with friends. Millions of effectively invisible closed-circuit television (CCTV) cameras and smart doorbells watch us in public, and we know facial recognition with artificial intelligence can put names to faces.

So how does being watched affect us? "It's one of the first topics to have been studied in psychology," says Clément Belletier, a psychologist at University of Clermont Auvergne in France. In 1898 psychologist Norman Triplett showed that cyclists raced harder in the presence of others. From the 1970s onward, studies showed how we change our overt behavior when we are watched to manage our reputation and social consequences.

But being watched doesn't just change our behavior; decades of research show it also infiltrates our mind to impact how we think. And now a new study reveals how being watched affects unconscious processing in our brain. In this era of surveillance, researchers say, the findings raise concerns about our collective mental health.

Related: 'I'd never seen such an audacious attack on anonymity before': Clearview AI and the creepy tech that can identify you with a single picture

Watchful eyes

Being looked at grabs our attention, as demonstrated by the stare-in-a-crowd effect: amid a sea of faces that aren't looking at us, we immediately detect a single one that is. This is because gaze direction, especially eye contact, is a powerful social signal that helps us to perceive others' intentions and predict their behavior.

Even as babies, a direct gaze quickly draws our attention. "These tendencies emerge very early" and are present across the animal kingdom, says Clara Colombatto, who studies social cognition at the University of Waterloo in Ontario. This ability likely evolved to detect predators, which may explain why being watched can provoke psychological discomfort and physical fight-or-flight responses, such as sweating.

On a conscious level, we behave differently when we are watched. We become more prosocial, meaning we're more likely to give and less likely to cheat or litter. Some studies have even suggested that theft or littering could be reduced merely by posting pictures of eyes. This kind of thinking led to the idea that surveillance could be used for social good — to prevent crime, for instance — echoing Bentham's methods for controlling incarcerated people.

The fact that people behave differently under watchful eyes isn't surprising. Who among us hasn't acted more selfishly when they were alone than they would when someone could see them? Psychologists put this down to concern with one's reputation.

But over the past few decades, researchers have found that being watched also affects cognitive functions such as memory and attention. For one thing, it can be very distracting. One study found that participants performed worse on a working memory task when they were presented with pictures of people looking at them compared with when they were shown pictures of people with averted eyes. The researchers concluded that a direct gaze grabs participants' attention and diverts their attentional resources from a given task. Other studies have found that more functions, ranging from our spatial cognition to language processing abilities, are similarly taxed by a watchful stare.

Unconscious effects

The effects of surveillance on cognition go even deeper — into our brain's unconscious processing of the world around us. In a study published last December, researchers showed that being watched accelerated participants' unconscious analysis of faces.

A team led by neuroscientist Kiley Seymour of the University of Technology Sydney used a technique called continuous flash suppression, or CFS, to measure how quickly people detected visual stimuli that initially escaped their conscious awareness. This technique involves presenting moving, colored patterns to one eye, which can delay awareness of images presented to the other eye. Previous studies showed that people would become aware of a suppressed image more quickly if it was more salient. For example, one CFS study found that participants became aware of faces looking at them faster than faces with averted eyes, showing that our brain processes gaze direction before we even know that we've seen anything.

Seymour and her colleagues wondered whether this unconscious processing might also be affected by knowing one is being watched. They had a group of people witness cameras being set up to send a live feed of them to another room. The participants were then shown faces that were suppressed by CFS, and they were asked to press buttons to indicate each face's location.

People in the "watched" group perceived faces faster and more accurately than those in the control group, who performed the same task without the overt surveillance. The difference was nearly a second. "That's big for these types of unconscious processes," says Colombatto, who was not involved in this study. Although the surveilled participants reported that they felt that they were being watched, they did not think this affected their performance. The effect was specific to faces — it did not occur for neutral stimuli such as abstract patterns — meaning being watched didn't just increase arousal or effort across the board. The fact that this unconscious process is influenced by inferring an observer's presence "shows just how sophisticated social perception is," Colombatto says.

In the past, researchers assumed the effects of being watched come from seeing people's eyes, but Colombatto and her colleagues found that pictures of mouths that were directed toward participants negatively impacted working memory. The team has also shown that mouths that are presented using CFS enter conscious awareness faster if they're directed toward participants rather than away from them. This even works with abstract geometric shapes that can point toward or away from a person, such as cones.

"These effects aren't really just about eyes. They're more general effects of people's minds and attention being directed toward you.... We call these effects of 'mind contact,'" Colombatto says. "It's really about being the object of someone's attention."

Unseen consequences

Surveillance, then, seems to shift our social processing into high gear. "The conclusion would be that being watched drives this hardwired survival mechanism into overdrive," Seymour says. "You're in fight-or-flight mode, which is taxing on the brain."

How might today's ubiquitous electronic eyes affect our mental health? The toll could be worse for people with schizophrenia, who, Seymour's research suggests, may be hypersensitive to others' gaze. Other conditions, such as social anxiety, also feature hypersensitivity to social cues, and that results in feelings of distress. "I'd say the modern world's constant surveillance is shifting us all in that direction, to some degree," Seymour says, "meaning we're all more attuned to our social environment and on edge, ready to react."

In the Panopticon, inmates always know a guard could be watching but never if one truly is. This is the key to the prison's power, argued French philosopher Michel Foucault: it becomes omniscient and internalized by the prisoners themselves. This may be why Bentham's prison feels so relevant in our digital age of algorithms, data brokers and social media, when we frequently feel watched — but we don't know who is watching.

This constant surveillance could tax cognition in ways that we don't yet understand. The faculties compromised by surveillance "are those that allow us to focus on what we're doing: attention, working memory, and so on," Belletier says. "If these processes are taxed by being monitored, you'd expect deteriorating capacity to concentrate." This body of research suggests that bringing more surveillance into workplaces — usually an attempt to boost productivity — could actually be counterproductive. It also suggests that online testing environments, where students are watched through webcams by human proctors or AI, could lead to lower performance.

"We didn't have as much surveillance and social connections 50 years ago, so it's a new societal context we're adapting to," Colombatto says. "It's important to think about how this is going to change our cognition, even in unconscious ways."

This article was first published at Scientific American. © ScientificAmerican.com. All rights reserved. Follow on TikTok and Instagram, X and Facebook.

What does it mean to live a good life? For centuries, philosophers, scientists and people of different cultures have tried to answer this question. Each tradition has a different take, but all agree: The good life is more than just feeling good — it's about becoming whole.

More recently, researchers have focused on the idea of flourishing, not simply as happiness or success, but as a multidimensional state of well-being that involves positive emotions, engagement, relationships, meaning and accomplishment — an idea that traces back to Aristotle's concept of "eudaimonia" but has been redefined within the well-being science literature.

Flourishing is not just well-being and how you feel on the inside. It's about your whole life being good, including the people around you and where you live. Things such as your home, your neighborhood, your school or workplace, and your friends all matter.

We are a group of psychological scientists, social scientists and epidemiologists who are all contributors to an international collaboration called the Global Flourishing Study. The goal of the project is simple: to find patterns of human flourishing across cultures.

Do people in some countries thrive more than others? What makes the biggest difference in a person's well-being? Are there things people can do to improve their own lives? Understanding these trends over time can help shape policies and programs that improve global human flourishing.

Related: What is mental health?

What does the flourishing study focus on?

The Global Flourishing Study is a five-year annual survey of over 200,000 participants from 22 countries, using nationally representative sampling to understand health and well-being. Our team includes more than 40 researchers across different disciplines, cultures and institutions.

With help from Gallup Inc., we asked people about their lives, their happiness, their health, their childhood experiences, and how they feel about their financial situation.

The study looks at six dimensions of a flourishing life:

1. Happiness and life satisfaction: how content and fulfilled people feel with their lives.
2. Physical and mental health: how healthy people feel, in both body and mind.
3. Meaning and purpose: whether people feel their lives are significant and moving in a clear direction.
4. Character and virtue: how people act to promote good, even in tough situations.
5. Close social relationships: how satisfied people are with their friendships and family ties.
6. Financial and material stability: whether people feel secure about their basic needs, including food, housing and money.

We tried to quantify how participants are doing on each of these dimensions using a scale from 0 to 10. In addition to using the Secure Flourish measure from Harvard's Human Flourishing Program, we included additional questions to probe other factors that influence how much someone is flourishing.

For example, we assessed well-being through questions about optimism, peace and balance in life. We measured health by asking about pain, depression and exercise. We measured relationships through questions about trust, loneliness and support.

Who is flourishing and why?

Our first wave of results reveals that some countries and groups of people are doing better than others.

We were surprised that in many countries young people are not doing as well as older adults. Earlier studies had suggested well-being follows a U-shape over the course of a lifespan, with the lowest point in middle age. Our new results imply that younger adults today face growing mental health challenges, financial insecurity and a loss of meaning that are disrupting the traditional U-shaped curve of well-being.

Married people usually reported more support, better relationships and more meaning in life.

People who were working — either for themselves or someone else — also tended to feel more secure and happy than people who were seeking jobs.

People who go to religious services once a week or more typically reported higher scores in all areas of flourishing — particularly happiness, meaning and relationships. This finding was true in almost every country, even very secular ones such as Sweden.

It seems that religious communities offer what psychologists of religion call the four B's: belonging, in the form of social support; bonding, in the form of spiritual connection; behaving, in the cultivation of character and virtue through the practices and norms taught within religious communities; and believing, in the form of embracing hope, forgiveness and shared spiritual convictions.

But some people who attend religious services also report more pain or suffering. This correlation may be because religious communities often provide support during hard times, and frequent attendees may be more attentive to or more likely to experience pain, grief or illness.

Your early years shape how you do later in life. But even if life started off as challenging, it doesn't have to stay that way. Some people who had difficult childhoods, having experienced abuse or poverty, still found meaning and purpose later as adults. In some countries, including the U.S. and Argentina, hardship in childhood seemed to build resilience and purpose in adulthood.

Globally, men and women report similar levels of flourishing. But in some countries there are big differences. For example, women in Japan report higher scores than men, while in Brazil, men report doing better than women.

Where are people flourishing most?

Some countries are doing better than others when it comes to flourishing.

Indonesia is thriving. People there scored high in many areas, including meaning, purpose, relationships and character. Indonesia is one of the highest-scoring countries in most of the indicators in the whole study.

Mexico and the Philippines also show strong results. Even though these countries have less money than some others, people report strong family ties, spiritual lives and community support.

Japan and Turkey report lower scores. Japan has a strong economy, but people there report lower happiness and weaker social connections. Long work hours and stress may be part of the reason. In Turkey, political and financial challenges may be hurting people's sense of trust and security.

One surprising result is that richer countries, including the United States and Sweden, are not flourishing as well as some others. They do well on financial stability but score lower in meaning and relationships. Having more money doesn't always mean people are doing better in life.

In fact, countries with higher income often report lower levels of meaning and purpose. Meanwhile, countries with higher fertility rates often report more meaning in life. These findings show that there can be a trade-off. Economic progress might improve some things but weaken others.

The big picture

The Global Flourishing Study is helping us see that people all over the world want many of the same basic things: to be happy, healthy, connected and safe. But different countries reach those goals in different ways. There is no one-size-fits-all answer to flourishing. What it means to flourish can look different from place to place and from one person to another.

One challenge with the Global Flourishing Study is that it uses the same set of questions in all 22 countries. This method, known as an etic approach, helps us compare results across cultures. But it can miss the nuance and local meanings of flourishing. What brings happiness or purpose in one country or context might not mean the same thing in another.

We consider this study to be a starting point. It opens the door for more emic studies — research that uses questions and ideas that fit the values, language and everyday life of specific cultures and societies. Researchers can build on this study's findings to expand how we understand and measure flourishing around the world.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Is your green my green? Probably not. What appears as pure green to me will likely look a bit yellowish or blueish to you. This is because visual systems vary from person to person. Moreover, an object's color may appear differently against different backgrounds or under different lighting.

These facts might naturally lead you to think that colors are subjective. That, unlike features such as length and temperature, colors are not objective features. Either nothing has a true color, or colors are relative to observers and their viewing conditions.

But perceptual variation has misled you. We are philosophers who study colors, objectivity and science, and we argue in our book "The Metaphysics of Colors" that colors are as objective as length and temperature.

Related: Scientists hijacked the human eye to get it to see a brand-new color. It's called 'olo.'

Perceptual variation

There is a surprising amount of variation in how people perceive the world. If you offer a group of people a spectrum of color chips ranging from chartreuse to purple and asked them to pick the unique green chip — the chip with no yellow or blue in it — their choices would vary considerably. Indeed, there wouldn't be a single chip that most observers would agree is unique green.

Generally, an object's background can result in dramatic changes in how you perceive its colors. If you place a gray object against a lighter background, it will appear darker than if you place it against a darker background. This variation in perception is perhaps most striking when viewing an object under different lighting, where a red apple could look green or blue.

Of course, that you experience something differently does not prove that what is experienced is not objective. Water that feels cold to one person may not feel cold to another. And although we do not know who is feeling the water "correctly," or whether that question even makes sense, we can know the temperature of the water and presume that this temperature is independent of your experience.

Similarly, that you can change the appearance of something's color is not the same as changing its color. You can make an apple look green or blue, but that is not evidence that the apple is not red.

For comparison, the Moon appears larger when it's on the horizon than when it appears near its zenith. But the size of the Moon has not changed, only its appearance. Hence, that the appearance of an object's color or size varies is, by itself, no reason to think that its color and size are not objective features of the object. In other words, the properties of an object are independent of how they appear to you.

That said, given that there is so much variation in how objects appear, how do you determine what color something actually is? Is there a way to determine the color of something despite the many different experiences you might have of it?

Matching colors

Perhaps determining the color of something is to determine whether it is red or blue. But we suggest a different approach. Notice that squares that appear to be the same shade of pink against different backgrounds look different against the same background.

It's easy to assume that to prove colors are objective would require knowing which observers, lighting conditions and backgrounds are the best, or "normal." But determining the right observers and viewing conditions is not required for determining the very specific color of an object, regardless of its name. And it is not required to determine whether two objects have the same color.

To determine whether two objects have the same color, an observer would need to view the objects side by side against the same background and under various lighting conditions. If you painted part of a room and find that you don't have enough paint, for instance, finding a match might be very tricky. A color match requires that no observer under any lighting condition will see a difference between the new paint and the old.

That two people can determine whether two objects have the same color even if they don't agree on exactly what that color is — just as a pool of water can have a particular temperature without feeling the same to me and you — seems like compelling evidence to us that colors are objective features of our world.

Colors, science and indispensability

Everyday interactions with colors — such as matching paint samples, determining whether your shirt and pants clash, and even your ability to interpret works of art — are hard to explain if colors are not objective features of objects. But if you turn to science and look at the many ways that researchers think about colors, it becomes harder still.

For example, in the field of color science, scientific laws are used to explain how objects and light affect perception and the colors of other objects. Such laws, for instance, predict what happens when you mix colored pigments, when you view contrasting colors simultaneously or successively, and when you look at colored objects in various lighting conditions.

The philosophers Hilary Putnam and Willard van Orman Quine made famous what is known as the indispensability argument. The basic idea is that if something is indispensable to science, then it must be real and objective — otherwise, science wouldn't work as well as it does.

For example, you may wonder whether unobservable entities such as electrons and electromagnetic fields really exist. But, so the argument goes, the best scientific explanations assume the existence of such entities and so they must exist. Similarly, because mathematics is indispensable to contemporary science, some philosophers argue that this means mathematical objects are objective and exist independently of a person's mind.

Likewise, we suggest that color plays an indispensable role in evolutionary biology. For example, researchers have argued that aposematism — the use of colors to signal a warning for predators — also benefits an animal's ability to gather resources. Here, an animal's coloration works directly to expand its food-gathering niche insofar as it informs potential predators that the animal is poisonous or venomous.

In fact, animals can exploit the fact that the same color pattern can be perceived differently by different perceivers. For instance, some damselfish have ultraviolet face patterns that help them be recognized by other members of their species and communicate with potential mates while remaining largely hidden to predators unable to perceive ultraviolet colors.

In sum, our ability to determine whether objects are colored the same or differently and the indispensable roles they play in science suggest that colors are as real and objective as length and temperature.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Our teenagers are in trouble.

Headlines have been ringing loud alarms around adolescent mental health, and the data are sobering. In 2023, 40 percent of high school students surveyed by the Centers for Disease Control and Prevention said they persistently felt hopeless or sad in the past year. Nine percent had attempted suicide.

Some of it is because of COVID. Some of it is related to social media. Then there is bullying, the pressure to succeed academically, the pressure to fit in. Being a teenager in the U.S. is hard.

So it's perhaps heartening to see President Donald Trump address mental health in a recent executive order (EO) targeting chronic health issues in children, one released as soon as Robert F. Kennedy, Jr., was confirmed as the director of the Department of Health and Human Services.

But nestled in this directive, which creates an RFK, Jr.–chaired commission to "Make America Healthy Again," are words that speak to the doubt that he and Trump have tried to sow around established science. This includes suggestions that the research funded by the National Institutes of Health and other agencies isn't "gold standard" and assertions that doctors are overprescribing medicines for conditions such as attention deficit hyperactivity disorder and depression and that "medical treatments" might be part of the pediatric chronic disease problem. Perhaps most troubling is the language the administration uses to describe prescription medications for mood and behavior disorders — they are a "threat."

That language stigmatizes families who choose prescription medication to treat their struggling children. It undermines the expertise of medical professionals. And it opens the door for unproven, improperly studied treatments to gain legitimacy.

The next era of snake oil dawns. Won't anyone think of the children?

According to the CDC, in 2021 and 2022, more than half of U.S. teens talked to a health care provider about their mental health. About 14 percent of teens reported taking medication to manage their emotional state or for concentration and behavior. Yet 20 percent said they have unmet mental health needs.

The Affordable Care Act, and before it, the federal parity law, introduced a lot of Americans, including perhaps these teens' parents, to parity in mental health coverage — in theory, insurance plans can't deny mental health coverage, charge ridiculous rates for coverage that included mental health or put limits on the amount of mental health coverage a plan allows.

But even if you have insurance, depending on where you live, finding mental health care for children can be incredibly difficult. Many providers, whether therapists or psychiatrists, don't take insurance, or don't take certain plans. This includes Medicaid but also large commercial plans. Many primary care doctors, including pediatricians, have limits on what aspects of mental health care they are comfortable managing, including medication. In rural parts of the U.S., there are hundreds of counties that do not have a single child psychiatrist.

Related: At-home brain stimulation could be promising depression treatment, trial hints

Then there is the public education system, bound to provide a suitable education for all children, thrust in the role of mental health adviser. For many children in the U.S., appropriate services first become available when a teacher, an aide, a counselor or another professional says, 'Hey, I think this kid needs help,' or when a kid demonstrates concerning behavior. This is admirable and necessary — one estimate says about 70 percent of mental health services that kids get happen at school.

But now some states are suing the federal government to render Section 504 educational accommodations for those children, and others with disabilities, unconstitutional because it was modified by the Biden administration to recognize youth who are LGBTQ.

This is the cruelty and the inconsistency of this executive order. Children who are LGBTQ have some of the largest rates of depression and anxiety in this country. Some 41 percent considered suicide in 2022–2023. And now we have a government trying to erase their very being from health care data, or at least to tell people who visit certain federal health care websites that the administration doesn't believe the science and evidence around gender. (Those stats from the CDC come from reports that were temporarily pulled down at the beginning of the Trump administration as part of a push to remove references to gender and sexuality that do not align with the male-female binary that drives conservative ideology.)

So what might come of the Trump administration's decision to examine our children's mental health? Federal funding for conversion therapy to "cure" LGBTQ teen depression? RFK, Jr., steering taxpayer dollars to the addiction-treating labor camps that he calls "wellness farms"? Pushing clinical trials for hydroxychloroquine to treat mood disorders (remember this from COVID?) or promoting something like juicing as a treatment for depression? This is speculation, of course, but the broader question of whether Kennedy will, with the administration's blessing, use tax dollars to promote untested, ineffective or harmful treatments remains.

Kennedy is a litigator who is now running our nation's most comprehensive health care agency. He is not a doctor, not a health care specialist, but a litigator — and one who kept saying during his confirmation hearings that he wanted to see the data that support the health care he has been desperately trying to undermine for the past decade. He is a litigator who once called people on certain antidepression drugs "addicts" and who has (falsely) claimed that it is harder to quit selective serotonin reuptake inhibitors — drugs like Prozac — than heroin.

Meanwhile the second Trump administration guts health care agencies when it could be doing what the first Trump administration did during COVID and facilitating telemedicine so that more children can access therapy and psychiatry. The administration pulls data and questions, just for the sake of it, the validity of what data we have. The EO says the administration will work with insurers to increase access, but what does that mean? Our medical schools are not graduating enough child psychiatrists. And it's not clear if Trump will again go after foreign medical graduates, many of whom fill rural medicine shortages, including psychiatry.

Antidepressants do not work for everyone, and some are associated with suicidal thinking in children. Stimulants do not help all children with ADHD. But this is the case for nearly every class of medication in this country — what works for some will not work for others. In the meantime, only 14 percent of adolescents are getting medication, and one in five is telling us they need more help. How is this overprescribing?

Going after antidepressants and claiming — preposterously — that they are harder to wean off of than heroin isn't how we care for children. This commission need not waste any time trying to reinvent the wheel. If its members want to solve mental health disorders as a chronic health condition in children, they need to make evidence-based treatment easier to get, increase incentives for insurance and workforce development and stop stigmatizing the families and children who need — and benefit from — this form of health care.

This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.

This article was first published at Scientific American. © ScientificAmerican.com. All rights reserved. Follow on TikTok and Instagram, X and Facebook.

Why does it seem like the same dreams keep following us? Maybe you've dreamed of soaring like a bird since childhood, or you've recently started revisiting a particular place or time while asleep. Perhaps a bad day at work still stirs exam nightmares, even if you haven't been a student for decades.

If so, you're far from alone. Recurring dreams are a surprisingly common phenomenon: research shows that up to 75 percent of adults experience at least one during their lifetime. These dreams exist on a spectrum: sometimes they're nearly identical each time they occur, but they may also have recurring themes, locations or characters set against different backdrops. This fluctuation sets recurring dreams apart from bad dreams triggered by post-traumatic stress disorder, a psychological condition in which people relive specific memories from their waking life with far less variation while asleep. Experts are still uncertain about why we experience recurring dreams at all, but new research is helping better identify patterns in their frequency and content, as well as in the scenarios that provoke them.

Recent studies have bolstered the long-held idea that recurring dreams are often — but not always — bad ones. In a 2022 survey by Michael Schredl, head of the sleep laboratory at the Central Institute of Mental Health in Germany, and his colleagues, adults flagged recurring dreams as "negatively toned" two thirds of the time; these dreams often touched on themes such as being chased or attacked, arriving somewhere late or failing at something. The participants' positive recurring dreams, by contrast, involved themes such as flying or discovering a new room in their house.

The reasons why we might have a greater propensity for negative dreams are not fully understood, but Schredl says dreams typically overdramatize something in our waking life — even a small feeling or minor situation we feel powerless to change. "In the dream, it becomes a much bigger emotion, although the connection isn't always straightforward or obvious," he explains.

Psychology and neuroscience offer additional clues. For example, we are prone to what's known as negativity bias: a tendency to fixate more upon unpleasant thoughts, emotions or social interactions than on positive ones. This behavior is rooted in our subconscious need to resolve negative situations that threaten our survival. Negativity bias may be compounded in sleep because our dreaming brain dampens the areas associated with linear logic and activates portions associated with emotion, weakening the filter between our thoughts and our feelings.

Related: Do blind people 'see' images in their dreams?

Understanding the psychological underpinnings of recurrent dreams has been challenging to study because it's difficult to control dreams in an experimental context. But events like the 9/11 terrorist attacks or the COVID pandemic, those in which many people experience a shared trauma, have allowed scientists to investigate certain dream-related patterns in more detail.

People who live through regional or global catastrophes often experience a "striking" increase in negatively-toned recurring dreams afterward, says Deirdre Leigh Barrett, a dream researcher and author of the 2020 book Pandemic Dreams. During the pandemic, Barrett amassed more than 15,000 dream reports, and in twin publications — a book chapter and a study — she showed that repeated themes involving fear, illness and death were then two to four times more common in peoples' dreams than they were before the pandemic began. Common narratives included watching loved ones die, seeing swarms of insects (perhaps stemming from the description of COVID as a "bug," Barrett says) and experiencing disasters, such as tidal waves, that are emblematic of something all-consuming.

Barrett found that dreams early in the pandemic tended to be more literal and induced more fear and anxiety. Over time, they shifted toward less terrifying but still unpleasant situations related to social embarrassment, such as being the only person in public not wearing a face mask. "They're clearly somewhat linked to what's going on in our daily lives," Barrett says, referring to what is known as the "continuity hypothesis." "If you're not processing the emotions during the day, your nocturnal consciousness will attempt to process them at night," she explains.

Barrett and other experts emphasize that negative recurring dreams are common and normal and that there are actionable steps to control them. Some people have found success in a practice called imagery rehearsal therapy, in which they repeatedly reimagine their nightmares with happier endings before going to sleep. Nirit Soffer-Dudek, a consciousness researcher and clinical psychologist at Ben-Gurion University of the Negev in Israel, also recommends cultivating good "sleep hygiene." By setting a consistent sleep schedule, limiting screen use and avoiding caffeine or alcohol before bed, "you're less likely to fall asleep while still in a heightened emotional state," she says. "The best advice I can give is to try to enforce strong boundaries between your waking time and sleep to avoid bringing anxiety into your dreams."

This article was first published at Scientific American. © ScientificAmerican.com. All rights reserved. Follow on TikTok and Instagram, X and Facebook.

We all know that time seems to pass at different speeds in different situations. For example, time appears to go slowly when we travel to unfamiliar places. A week in a foreign country seems much longer than a week at home.

Time also seems to pass slowly when we are bored, or in pain. It seems to speed up when we're in a state of absorption, such as when we play music or chess, or paint or dance. More generally, most people report time seems to speed up as they get older.

However, these variations in time perception are quite mild. Our experience of time can change in a much more radical way. In my new book, I describe what I call "time expansion experiences" — in which seconds can stretch out into minutes.

The reasons why time can speed up and slow down are a bit of a mystery. Some researchers, including me, think that mild variations in time perception are linked to information processing. As a general rule, the more information — such as perceptions, sensations, thoughts — that our minds process, the slower time seems to pass. Time passes slowly to children because they live in a world of newness.

New environments stretch time because of their unfamiliarity. Absorption contracts time because our attention becomes narrow, and our minds become quiet, with few thoughts passing through. In contrast, boredom stretches time because our unfocused minds fill with a massive amount of thought-chatter.

Related: 'Flow state' uncovered: We finally know what happens in the brain when you're 'in the zone'

Time expansion experiences

Time expansion experiences (or Tees) can occur in an accident or emergency situation, such as a car crash, a fall or an attack. In time expansion experiences, time appears to expand by many orders of magnitude. In my research, I have found that around 85% of people have had at least one Tee.

Around a half of Tees occur in accident and emergency situations. In such situations, people are often surprised by the amount of time they have to think and act. In fact, many people are convinced that time expansion saved them from their serious injury, or even saved their lives — because it allowed them to take preventative action that would normally be impossible.

For example, a woman who reported a Tee in which she avoided a metal barrier falling on to her car told me how a "slowing down of the moment" allowed her to "decide how to escape the falling metal on us."

Tees are also common in sport. For example, a participant described a Tee that occurred while playing ice hockey, when "the play which seemed to last for about ten minutes all occurred in the space of about eight seconds." Tees also occur in moments of stillness and presence, during meditation or in natural surroundings.

However, some of the most extreme Tees are linked to psychedelic substances, such as LSD or ayahuasca. In my collection of Tees, around 10% are linked to psychedelics. A man told me that, during an LSD experience, he looked at the stopwatch on his phone and "the hundredths of a second were moving as slow as seconds normally move. It was really intense time dilation," he said.

But why? One theory is that these experiences are linked to a release of noradrenaline (both a hormone and an neurotransmitter) in emergency situations, related to the "fight or flight" mechanism. However, this doesn't fit with the calm wellbeing people usually report in Tees.

Even though their lives might be in danger, people usually feel strangely calm and relaxed. For example, a woman who had a Tee when she fell off a horse told me: "The whole experience seemed to last for minutes. I was ultra-calm, unconcerned that the horse still hadn't recovered its balance and quite possibly could fall on top of me." The noradrenaline theory also doesn't fit with the fact that many Tees occur in peaceful situations, such as deep meditation or oneness with nature.

Another theory I have considered is that Tees are an evolutionary adaptation. Maybe our ancestors developed the ability to slow down time in emergency situations — such as encounters with deadly wild animals or natural disasters — to improve their chances of survival. However, the above argument applies here too: this doesn't fit with the non-emergency situations when Tees occur.

A third theory is that Tees aren't real experiences, but illusions of recollection. In emergency situations, so this theory goes, our awareness becomes acute, so that we take in more perceptions than normal. These perceptions become encoded in our memories, so that when we recall the emergency situation, the extra memories create the impression that time passed slowly.

However, in many Tees, people are certain that they had extra time to think and act. Time expansion allowed complex series of thoughts and actions that would have been impossible if time had been passing at a normal speed. In a recent (not yet published) poll of 280 Tees, I found that less than 3% of the participants believed that the experience was an illusion. Some 87% believed it was a real experience that happened in the present, while 10% were undecided.

Altered states of consciousness

In my view, the key to understanding Tees surrounds altered states of consciousness. The sudden shock of an accident may disrupt our normal psychological processes, causing an abrupt shift in consciousness. In sport, intense altered states occur due to what I call "super-absorption."

Absorption normally makes time pass faster — as in flow, when we are absorbed in a task. But when absorption becomes especially intense, over a long period of sustained concentration, the opposite occurs, and time slows down radically.

Altered states of consciousness can also affect our sense of identity, and our normal sense of separation between us and the world. As the psychologist Marc Wittmann has pointed out, our sense of time is closely bound up with our sense of self.

We usually have a sense of living inside our mental space, with the world "out there" on the other side. One of the main features of intense altered states is that sense of separation fades. We no longer feel enclosed inside our minds, but feel connected to our surroundings.

This means the boundary between us and the world softens. And in the process, our sense of time expands. We slip outside our normal consciousness, and into a different time-world.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Former New Zealand prime minister John Key has three white rabbits painted on his helicopter, a nod to his "massively superstitious" habit of repeating "white rabbits" three times at the start of every month.

Tennis champion Rafael Nadal performs the same sequence of actions (shirt-tug, hair-tuck, face-wipe) before every serve. Taylor Swift paints "13" on her hand for good luck before a show, while Rihanna won't allow anything yellow in her dressing room.

Perhaps you, too, are superstitious. Maybe you have a lucky number, avoid black cats, or shudder at the thought of opening an umbrella indoors.

Even if you don't consider yourself superstitious, little things like saying "bless you" after a sneeze, knocking on wood or crossing your fingers are all examples of behaviors with superstitious origins.

We humans are particularly susceptible to superstitions. But why are we so quick to develop superstitious behaviors, and do we really believe they can bring good or bad luck?

In our new research, we set out to answer this question. We tested whether people could tell the difference between outcomes they caused and outcomes they didn't cause, and this told us something about the cognitive roots of human superstition.

Related: From black cats to white spirit bears, 'superstitions, lore and myths can shape your subconscious' − biases that have real effects

Learning about cause and effect

From as early as four months, infants learn their actions produce outcomes — kicking their legs shakes the crib, shaking a rattle makes an interesting noise, dropping a toy on the floor means mum or dad picks it up.

As we grow older, we develop a more sophisticated understanding of cause-and-effect relationships, asking "why?" questions about the world around us.

This sensitivity to causes and effects sets the stage for important developmental milestones, like imaginative play, planning actions to achieve a goal, predicting others' intentions, anticipating and regulating emotions, and cooperating with others.

The ability to learn about relationships between causes and effects is a defining feature of human cognition. But how does this square with our superstitious tendencies?

When cause and effect is an illusion

We learn about causes and effects from experience. When our behavior is followed by an outcome, we learn about the relationship between our action and that outcome. The more often this action-outcome pairing occurs, the stronger the perceived link between them.

This is why we repeat behaviors that produce rewarding outcomes, and avoid repeating behaviors that produce punishing ones.

But what happens if an outcome follows our actions by coincidence? If I wear my lucky socks and my favorite sports team wins, this is probably just a coincidence (it's unlikely my sock-wearing actually caused the win). But if this happens a few times, I may develop a superstition about my lucky socks.

This suggests superstitious behavior arises because we aren't particularly good at discerning when our actions cause an outcome, versus when our actions just coincide with (but do not cause) an outcome. This is a common explanation for superstition — but does it have any weight?

Testing our ability to detect causality

We can test what underpins superstitious behavior by simply asking people "who caused that outcome?". Getting it right would suggest we can discern action-outcome relationships (and therefore that there must be some other explanation for superstitious behavior).

Our research did exactly that. We asked whether people could tell when their actions did or didn't cause an outcome.

We recruited 371 undergraduate students from a large New Zealand university, who participated in one experimental session for a course credit. Participants played a game where a positive outcome (winning) or a negative outcome (losing) occurred either after their own action (clicking a button), or independently of their action.

Importantly, participants weren't given any information beforehand about the type of outcome or whether it would depend on their behavior. This meant they had to rely on what they actually experienced during the game, and we could test their ability to judge whether they had caused the outcome.

This also meant participants' preexisting superstitions and other characteristics (such as age) didn't affect our results. Their behavior during the task was representative of human behavior more generally.

Participants' scores indicated they often got it right: in about 80% of trials, they knew when they'd caused the outcome, and when they hadn't.

A built-in bias

The distinction between causing and not causing the outcomes was sometimes very subtle. This made it more difficult for participants to tell what had occurred.

When they weren't sure, participants defaulted to saying "I caused it", even if they actually hadn't. They were biased to attribute outcomes to their own actions, particularly after winning outcomes.

This bias may be the key to explaining why we're superstitious: something I did caused something to happen, even if I can't be sure what it was. And it suggests knowing superstitions aren't real may not actually stop us from behaving superstitiously.

On the surface, this may not make sense — why expend energy doing things we know don't affect outcomes? But if we look deeper, this bias serves an important purpose, because it helps ensure we don't miss any potential connections between our actions and their outcomes. In other words, it's better to be safe than sorry.

Research shows that engaging in superstitious behavior can also increase confidence in our abilities to achieve a goal, improve performance in different tasks, and alleviate anxiety by giving us a sense of control.

The tendency to attribute positive outcomes to our actions (as we found) can boost self-esteem and psychological wellbeing. So, perhaps we'd all benefit by indulging in a little superstitious behavior. Touch wood.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Psychology is a relatively young science. The first person to call himself a psychologist, Wilhelm Maximilian Wundt, began his work in the 1860s in Germany and established the first-ever psychology lab in 1879. In the early 1900s, the science of behaviorism arose. It focused less on the internal processes of the mind and more on how people acted under given circumstances, some of which could be quite unusual, depending on the experiment.

Over the past century, psychologists have come up with a variety of creative (and sometimes questionable) ways to study the human mind and behavior. Some of these experiments occurred before strong protections for participants' safety; others were ethical but went to strange lengths to isolate a single variable or outcome. Test yourself on the weird history of some of psychology's most infamous studies here.

More science quizzes

—Equator quiz: Can you name the 13 countries that sit on Earth's central line?

—Ancient Egypt quiz: Test your smarts about pyramids, hieroglyphs and King Tut

—Moon landing quiz: How quickly can you name all 12 Apollo astronauts that walked on the moon?

—Crocodile quiz: Test your knowledge on the prehistoric predators

Attachment styles are a popular way to understand how people experience relationships and why they might struggle to be vulnerable with loved ones. They're a popular topic of conversation — in online spaces, especially — so you may be familiar with terms like "secure" and "insecure" attachment, or "anxious" and "avoidant" attachment.

But is there real science behind attachment styles?

The short answer is yes — but there are plenty of misconceptions about what a person's attachment style can tell you about them.

Psychologists use attachment styles to describe people's approach to relationships. However, these styles do not necessarily rule people's relationships, nor can people always be neatly categorized into these different ways of interacting. Instead, attachment styles occur along a continuum, and people may be "secure" in some types of relationships and "insecure" in others.

Related: Was Freud right about anything?

"There isn't a magical threshold at which a person suddenly becomes secure or insecure," said R. Chris Fraley, a social and personality psychologist at the University of Illinois at Urbana-Champaign who studies attachment. Nor is there a set amount of relationship-related trauma in someone's past that determines their attachment style, Fraley told Live Science. People vary widely in how they react to poor parenting or untrustworthy romantic partners, for instance.

What are the different attachment styles?

The styles come from attachment theory, which arose in the late 1960s out of work conducted by psychologists John Bowlby and Mary Ainsworth. Bowlby hypothesized that if young children did not form secure attachments with a primary caregiver in toddlerhood, they would struggle to do so for a lifetime.

To test this idea, Ainsworth devised an experiment in which babies around age 1 were left by their parent to play alone in an unknown room for a few minutes. Then, the parent would return. Psychologists would observe how the child reacted to both the parent's departure and return.

From these observations, Ainsworth posited four attachment styles:

• Secure attachment: Securely attached babies were upset at their parent's departure and were immediately comforted when the parent returned.
• Anxious attachment: Anxiously attached babies were upset at their parent's departure and difficult to console when the parent returned.
• Avoidant attachment: Avoidantly attached babies barely reacted to their parent's departure or return.
• Disorganized attachment: Disorganized attached babies had unpredictable responses to their parent either coming or going. They could become very anxious or distressed, which could manifest as uncontrollable outbursts or a flat, seemingly unemotional affect.

Over time, other psychologists began to consider these attachment styles in the context of adult relationships.

There are different ways to measure attachment, but one common method that social and personality psychologists use is to measure a person's attachment-related avoidance and attachment-related anxiety, usually via questionnaires about their relationships and behaviors.

Someone who is avoidant in a relationship shies away from intimacy or opportunities to disclose their emotions; they have difficulty trusting others and may push people away if they feel they are getting too close. Meanwhile, someone who is anxious in a relationship feels insecure, worries that the other person does not really care about them, and thus may become clingy and uncomfortably dependent on their partner.

Someone low in both avoidance and anxiety is considered securely attached, Fraley said.

"We consider someone to be 'secure' in their relationship if they are comfortable depending on the person in question, using them as a safe haven in times of distress, and are assured that the person is truly invested in their well-being," he said.

On average, there is an association between people's early childhood experiences and their adult attachment styles, Fraley said. People who experience early life abuse, neglect, or otherwise cold or unpredictable caregiving are more likely to struggle with attachment in adult relationships. However, he said, childhood experiences don't cement your fate — there are many people who encounter bad experiences early in life but have secure adult relationships, and vice versa.

"People change, relationship experiences change, and life gets complicated in ways that can't be captured simply by knowing what happened early in a person's life," Fraley said. "Most attachment scholars think of attachment as reflecting the history of a person's interpersonal experiences rather than something that happened at one specific point in time. Although people tend to have some continuity in their interpersonal histories, those twists and turns matter too."

In other words, attachment styles can change.

"Fairly simple strategies, such as simply reflecting on and writing about attachment experiences, can lead to short-term boosts in security," Fraley noted. "What we don't understand well is what it takes to create and sustain longer-term change."

Researchers are working to answer that question, Fraley said. In the meantime, he and his colleagues run a website with scientifically validated attachment style questionnaires for anyone wondering what their own styles in their own relationships might be.

This article is for informational purposes only and is not meant to offer relationship or mental health advice.

We often joke that our attention spans have dropped significantly in recent years with the rise of digital technologies and screen-centric entertainment, but there is sound science to back up this observation. In fact, a shorter attention span is simply one side effect of a recent explosion of screen distractions, as neurologist and author Richard E. Cytowic argues in his new book, "Your Stone Age Brain in the Screen Age: Coping with Digital Distraction and Sensory Overload" (MIT Press, 2024).

In his book, Cytowic discusses how the human brain has not changed significantly since the Stone Age, which leaves us poorly equipped to handle the influence and allure of modern technologies — particularly those propagated by big tech companies. In this excerpt, Cytowic highlights how our brains struggle to keep up with the lightning-fast pace at which modern technology, culture and society are changing.

From an engineering perspective, the brain has fixed energy limits that dictate how much work it can handle at a given time. Feeling overloaded leads to stress. Stress leads to distraction. Distraction then leads to error. The obvious solutions are either to staunch the incoming stream or alleviate the stress.

Hans Selye, the Hungarian endocrinologist who developed the concept of stress, said that stress "is not what happens to you, but how you react to it." The trait that allows us to handle stress successfully is resilience. Resilience is a welcome trait to have because all demands that pull you away from homeostasis (the biological tendency in all organisms to maintain a stable internal milieu) lead to stress.

Screen distractions are a prime candidate for disturbing homeostatic equilibrium. Long before the advent of personal computers and the internet, Alvin Toffler popularized the term “information overload” in his 1970 bestseller, Future Shock. He promoted the bleak idea of eventual human dependence on technology. By 2011, before most people had smartphones, Americans took in five times as much information on a typical day as they had twenty-five years earlier. And now even today’s digital natives complain how stressed their constantly present tech is making them.

Visual overload is more likely a problem than auditory overload because today, eye-to-brain connections anatomically outnumber ear-to-brain connections by about a factor of three. Auditory perception mattered more to our earliest ancestors, but vision gradually took prominence. It could bring what-if scenarios to mind. Vision also prioritized simultaneous input over sequential ones, meaning that there is always a delay from the time sound waves hit your eardrums before the brain can understand what you are hearing. Vision’s simultaneous input means that the only lag in grasping it is the one-tenth second it takes to travel from the retina to the primary visual cortex, V1.

Smartphones easily win out over conventional telephones for anatomical, physiological, and evolutionary reasons. The limit to what I call digital screen input is how much the lens in each eye can transfer information to the retina, the lateral geniculate, and thence to V1, the primary visual cortex. The modern quandary into which we have engineered ourselves hinges on flux, the flow of radiant energy that bombards our senses from far and near. For eons, the only flux human sense receptors had to transform into perception involved sights, sounds, and tastes from the natural world. From that time to the present we have been able to detect only the tiniest sliver of the total electromagnetic radiation that instruments tell us is objectively there. Cosmic particles, radio waves, and cellphone signals pass through us unnoticed because we lack the biological sensors to detect them. But we are sensitive, and highly so, to the manufactured flux that started in the twentieth century and lies on top of the natural background flux.

Our self-created digital glut hits us incessantly, and we cannot help but notice and be distracted by it. Smartphone storage is measured in tens of gigabytes and the hard drive of a computer in terabytes (1,000 gigabytes), while data volumes are calculated in petabytes (1,000 terabytes), zettabytes (1,000,000,000,000 gigabytes), and beyond. Yet humans still have the same physical brain as our Stone Age ancestors. True, our physical biology is amazingly adaptive, and we inhabit every niche on the planet. But it cannot possibly keep up with the breathtaking speed at which modern technology, culture, and society are changing. Attention spans figure prominently in debates about how much screen exposure we can handle, but no one considers the energy cost involved.

A much-cited study conducted by Microsoft Research Canada claims that attention spans have dwindled to below eight seconds — less than that of a goldfish — and this supposedly explains why our ability to focus has gone to hell. But that study has shortcomings, and “attention span” is a colloquial term rather than a scientific one. After all, some people’s Stone Age brains have the capacity to compose a symphony, monitor the data stream from a nuclear reactor or the space station, or work out heretofore unsolvable problems in mathematics. Individual differences exist in the capacity and ability to cope with stressful events. To give California its due, Gloria Mark at the University of California, Irvine, and her colleagues at Microsoft measured attention spans in everyday environments. In 2004, people averaged 150 seconds before switching from one screen to another. By 2012 that time had fallen to 47 seconds. Other studies have replicated these results. We are determined to be interrupted, says Mark, if not by others, then by ourselves. The drain on our switching is "like having a gas tank that leaks." She found that a simple chart or digital timer that prompts people to take periodic breaks helps a lot.

Neuroscience distinguishes sustained attention, selective attention, and alternating attention. Sustained attention is the ability to focus on something for an extended period. Selective attention speaks to the aptitude for filtering out competing distractions to stick with the task at hand. Alternating attention is the capacity to switch from one task to another and back again to where you left off. In terms of the energy cost incurred by repeatedly shifting attention throughout the day, I fear we have hit the brain’s Stone Age limit. Exceeding it results in foggy thinking, reduced focus, thought blocking, memory lapse or precision calipers, any tool quickly comes to feel like an extension of oneself. The same applies to smart devices. Two centuries ago when the first steam locomotives reached a blistering speed of thirty miles per hour, alarmists warned that the human body could not withstand such speeds. Since then ever-faster cars, communication methods, jet planes, and electronics have diffused into the culture and become absorbed into daily life. In earlier times fewer new technologies appeared per decade, fewer people were alive, and society was much less connected than it is today.

By contrast, the invention, proliferation, and evolution of digital technology have put the status quo in constant flux. Unlike analog counterparts such as a landline telephone or a turntable, smart devices repeatedly demand and command our attention. We have conditioned ourselves to respond to texts and incoming calls the moment they arrive. Admittedly, sometimes jobs and livelihoods do depend on an immediate response. Yet we pay a price in terms of energy cost incurred by constantly shifting and refocusing attention.

This excerpt has been edited for style and length. Reprinted with permission from "Your Stone Age Brain in the Screen Age: Coping with Digital Distraction and Sensory Overload" by Richard E. Cytowic, published by MIT Press. All rights reserved.

Ritual Aztec whistles produced a brain-scrambling "scream," according to a new study. The objects were used during human sacrifices and may have prepared victims for their supposed descent to Mictlan, the Aztec underworld.

The Aztecs created the small 1.2 to 2-inch-long (3 to 5 centimeters) skull-shaped whistles out of clay, possibly to represent Mictlantecuhtli, the Aztec lord of the underworld.

The skull whistles "trigger a medium level of urgency responses in listeners," and many listeners said the sound was akin to a "scream," study lead author Sascha Frühholz, a neuroscientist at the University of Zurich, said in a statement.

Archaeologists have recovered the whistles from the graves of people they assumed were sacrificial victims. "The whistles have a very unique construction, and we don't know of any comparable musical instrument from other pre-Columbian cultures," Frühholz said.

In the study, published Nov. 11 in the journal Communications Psychology, Frühholz and colleagues recruited 70 people to listen to more than 2,500 sound samples made by skull whistles.

Three of the whistles they used were modern reproductions, and the two others were whistles found at the Aztec site of Tlatelolco, near the Aztec capital of Tenochtitlán in what is now Mexico City.

The whistles all made "a shrill, piercing, and scream-like sound quality when played with intensive air pressure," the team wrote in the study.

Related: Remains of Aztec dwelling and floating gardens unearthed in Mexico City

The researchers also recorded the listeners' brains to identify which regions responded to the sounds.

The researchers discovered that the death whistle lit up brain regions associated with emotional responses and with identifying symbolic meaning. Aztec communities may therefore have used the scary sounds in specific ritual contexts, such as ceremonies involving death.

"Skull whistles might have been used to scare the human sacrifice or the ceremonial audience," the researchers wrote. However, there are limitations to the study that could benefit from further research, they noted.

"Unfortunately, we could not perform our psychological and neuroscientific experiments with humans from ancient Aztec cultures. But the basic mechanisms of affective response to scary sounds are common to humans from all historical contexts," Frühholz said.

Intense stress can lead to fuzzy memories, which can lead to more generalized fear responses. Now, scientists may have just discovered why.

A study in mice, published Friday (Nov. 15) in the journal Cell, suggests that stress hormones can distort how memories are recorded, leading to less-precise recollections and a future tendency to be unable to properly distinguish between safe triggers and threats.

The new findings could help uncover new avenues to treat people with post-traumatic stress disorder (PTSD) and generalized anxiety disorder.

"This is a tour de force study answering an age-old question that has not been answered — How does a traumatic or highly stressful experience increase fear generalization?" Denise Cai, an associate professor of neuroscience at the Icahn School of Medicine at Mount Sinai who wasn't involved in the study, told Live Science in an email.

Scientists have long known that acute stress changes how memories are encoded, said study lead author Sheena Josselyn, a memory researcher at The Hospital for Sick Children and the University of Toronto.

For example, a person exposed to gunfire might later feel intense fear after a loud noise, which is an inappropriate response. This is called fear overgeneralization.

Josselyn and colleagues set out to understand what happens in the brain as these memories are formed.

They restricted lab mice's movements for 30 minutes — an acutely distressing experience for the rodents. The mice were then trained to recognize two specific noises — one that preceded an uncomfortable electric shock, and one that didn't. As expected, the stressed mice did not remember the noise well and instead became scared of many sounds.

A closer look at these mice's brains revealed that the stress affected the traumatic event's "engram," the physical trace of a memory left behind as a group of neurons changes to encode the memory.

A typical engram tends to be quite "sparse," using a small number of brain cells, Josselyn told Live Science. This ensures that recollections don't get muddled together, she said. After exposure to stress, however, the engrams became larger, the team found.

This is because strong stress blocked inhibitory interneurons, or cells that typically regulate how excitable other neurons are. These cells usually act as gatekeepers that limit how many neurons are looped into an engram, the study found.

"These are like the bouncers at the nightclub that keep out the riffraff: Only the most excitable neurons are allowed into this nightclub and become part of the engram," Josselyn said.

By triggering the release of corticosterone, the mouse equivalent of the human stress hormone cortisol, stress sparked the release of a neurotransmitter called endocannabinoid, which then blocked the action of the inhibitory interneurons.

The fact that more neurons are encoding a traumatic memory may explain both why these memories can be hazy and why people tend to overgeneralize fear from the original event to other experiences.

Importantly, administering metyrapone, a chemical that inhibits the synthesis of corticosterone, before the mice were exposed to the stress reversed that effect without altering the memory of the original stressful event.

Because the study was done on mice, it's not yet clear whether the results can be applied to humans, Josselyn said.

Still, by providing insights into how stress can lead to the overgeneralization of memory, the study could help researchers develop targeted treatments to counteract the effect without affecting other memories, Cai said.

"This has a lot of translational relevance for mental health disorders, such as PTSD and generalized anxiety disorder," she said.

The study also raises questions about the use of cannabis in the context of PTSD, Josselyn said.

A few clinical trials are studying whether cannabinoids or cannabis products could treat PTSD and other anxiety disorders, but the field is still in its infancy. As a result, the US Department of Veteran Affairs recommends against the use of cannabis products in the treatment of PTSD. Still, anecdotal reports suggest some people with PTSD have been using cannabis, possibly to self-medicate, Josselyn said.

"People are using a lot of cannabis for recreational and halfway-medicinal purposes. But the scary thing is that we really don't understand a lot of the effects of cannabinoids" in PTSD, she said. "That really means we absolutely need to study this."

The practice of forest bathing is a mindful, meditative experience where we allow our senses to become attuned to nature by spending time walking through woodlands. Numerous studies have shown that immersing ourselves in the natural world in this way can have significant health benefits, but could we ever bring this practice to a clinical setting? Could nature immersion provide alternative and effective treatments to patients suffering from a wide range of ailments?

The answer to that question is the subject of the new book "Good Nature" by Kathy Willis, a professor of biodiversity at the University of Oxford. In it, she draws on the available evidence to show not just the health benefits of being surrounded by nature, but also the quantitative data that shows how doctors could prescribe time in the natural environment when forming treatment plans for their patients.

By exploring how different forms of nature interact with the body, she discovers how touching wood makes us calmer, the long lasting effects of walking through a pine forest, and why urban sounds are so annoying.

In this interview, she spoke to Live Science about what made her investigate the impact of nature, how looking at savannas can make us feel more relaxed, and why we should be filling our houses with spider plants.

Related: 'The prescription is nature': How satellites can show us the healing effects of nature

Alexander McNamara: Why did you first explore the impact nature had on health?

Kathy Willis: I was working on a large intergovernmental project looking at the ecosystem services provided by nature when I kept coming across this paper that really piqued my interest. It showed that gallbladder operation patients who could look out the window and see trees had less drugs for pain and they recovered much faster than those who looked onto brick walls.

I was interested in the fact that it wasn't that the trees were cleaning the air and the air was better, therefore the people were better. It was that there was a direct relationship between your sense of sight and recovery rate. It seemed to be some mechanism happening in the body that was resulting in faster recovery rates and less pain, related to seeing nature.

And that's where the whole journey for me started, thinking about what is going on, how does that work?

AM: I guess we take it for granted that we see all the plants and nature around us, but we overlook that as well as a psychological impact on us, it can actually have a physiological one too.

KW: Yes, with this study it was showing a direct physiological response to seeing green and I was interested to know what happened in the body to actually make them recover faster. But then I started to look at the other senses. What happens when we smell, when we hear, when we touch nature? And what's the medical evidence to show that it does [cause] a change?

What came through from this is that absolutely, there are significant changes that occur in our bodies when our senses interact with particular types of nature, but also it's an automatic response. We have nothing to do with it. So for example it'll be a change in your hormone levels, your adrenaline hormone will go down or your heart rate variability is enhanced.

These are the sort of things that if you want to convince a medic you can't say you just feel generally better, you have to give them quantitative evidence that shows what's happening. That's what I'm trying to do [with the book].

AM: So what is the mechanism for that in my body when I look at something green?

KW: When you look at the color green —and green and white leaves in particular are good — we've got three pathways that are affected through that visualization. The first ones affect the autonomic nervous system, so your heart rate and your blood pressure goes down. The second one is your endocrine system — your hormones — and for example you get a change in your salivary amylase levels, which is one that shows stress levels are reduced. The third one is your psychological index, which is the sort of thing that a psychiatrist will do to show people feel much calm and a lot less anxious.

AM: Is this response something that we have evolved?

KW: It may well be, and it's quite interesting because we have a particular response to different shapes of horizons. Think about an open landscape with a few oak trees, or a conifer outline, which is very pointy, versus a very angled and squared urban outline. What studies have shown is that when we look at the horizon, our eyes are picking out the fractal dimension [the complexity of an image's detail], and we automatically tend to go for fractal dimensions which are mid complexity [1.3]. I've done it many times with audiences, and people put their hand up to say which horizon makes them feel most relaxed. People always choose the more open landscape with a few scattered trees on it, which is 1.3.

Those tree shapes are reminiscent of savanna [landscape], and there was a really nice study where they showed photos of different landscapes to teenage children and young adults from West Africa. They would live their whole life in tropical rainforest and hadn't traveled, and yet they still picked the open savanna landscape as the one that they most liked.

AM: I guess all the senses must be impacted in some way by just being surrounded by nature?

KW: Yes, but the point is that it's not all nature, it's specific types. The chapter that most surprised me was the one on smell. Before I started researching smell, I just assumed you walk somewhere, breathe in a nice scent and then breathe it out again. But actually, when you breathe in a plant scent, those molecules are volatile organic compounds [VOCs] that pass across your lung membrane into your blood. So if you walk in a pine forest you have higher levels of pinene in your blood and that is interacting with the same biochemical pathways as taking a prescription drug for [a] particular thing [such as anxiety].

Really interesting studies have been done when you breathe in, particularly from the Cupressaceae family and the cedar family. [In experiments, when people inhale VOCs from these trees] it not only reduces their adrenaline hormone, but elevates the natural killer cells in their blood. And the natural killer cells are the things that attack cancers or viruses.

There's a lovely study published in Oncotarget, a cancer journal. [In it] they had looked at people who lived close to Cupressaceae forest versus those who live further away — the ones that live beside the forests were much healthier, with much less occurrences of many autoimmune type diseases. [Also] they entered a group into a Cupressaceae forest and measured their nature killer cells. After the five-hour walk, they had really elevated natural killer cells in their bloods [but] even more important was that seven days later, they still had greatly elevated natural killer cells in their bloods. So there's not only short-term, but also long-term benefits.

AM: Are there any benefits to having artificial plants instead of the real ones?

There's not been that many studies done on it, but there was a lovely one on Japanese schoolchildren where they were given a planter with real pansies in it. After they viewed it for 10 minutes, they said they felt calmer [and the researchers] said their blood pressure went down. Then they did the same [with] artificial plants, the ones made from a sort of polyester, and they're really, really convincing, but they got none of the benefits.

I think what it's showing is that it's not just sight, it must also be smell, subconsciously. The difference we get from smell is huge, and it's such an interesting and often completely ignored sense.

AM: Are there any other bodily systems that are affected by nature?

KW: We're learning so much about the gut and the gut flora, and how [it is affected by] going into a more biodiverse environment. Even just walking on the edge of the park, the more biodiversity you have at different levels, the higher the environmental diversity of that microbiome. And when you're in it, in the same way as smell, your body takes on the signature of the environment it's in.

They showed it beautifully with Finnish nursery children. In a study, [they observed children playing in] three nursery playgrounds, one had concrete, one had matting, and in the third one soil brought in from the Boreal forest. Over 28 days, the children played in the different areas, and then [the researchers] measured their gut microbiome, their skin [microbiome] and then they measured the inflammatory markers in their blood.

Those that played in the Boreal forest [soil] saw a completely new gut microbiome after 28 days, but not only that, these children also had this statistically significant reduction in inflammatory markers.

And then they showed the same with adults who had a green wall in their office versus no green wall. These plants and this biodiversity is seeding the environment that these people are in and they are adopting that signature as a result of it.

Given only 7% of our flora is inherited, the rest is driven by the environment, wherever we are, we should all really be heading towards the bushy edges.

AM: If we can't get outside so easily, are there any particular things we can do to bring nature into our homes?

KW: I think Victorians were much better at this than we are now but it's having a lot more plants around — live plants in your sitting room or in your study.

Even a vase of roses on your desk. There's been studies showing that [even] non-scented roses — so you're just seeing the flower of white and yellow roses — lower your blood pressure. Why not have a vase of roses on the desk? These are the sorts of things we can all do. We don't need to wait for someone to prescribe us.

Psychologists know that childhood trauma, or the experience of harmful or adverse events, can have lasting repercussions on the health and well-being of people well into adulthood. But while the consequences of early adversity have been well researched in humans, people aren't the only ones who can experience adversity.

If you have a rescue dog, you probably have witnessed how the abuse or neglect it may have experienced earlier in life now influence its behavior — these pets tend to be more skittish or reactive. Wild animals also experience adversity. Although their negative experiences are easy to dismiss as part of life in the wild, they still have lifelong repercussions — just like traumatic events in people and pets.

As behavioral ecologists, we are interested in how adverse experiences early in life can affect animals' behavior, including the kinds of decisions they make and the way they interact with the world around them. In other words, we want to see how these experience affect the way they behave and survive in the wild.

Many studies in humans and other animals have shown the importance of early life experiences in shaping how individuals develop. But researchers know less about how multiple, different instances of adversity or stressors can accumulate within the body and what their overall impact is on an animal's well-being.

Wild populations face many kinds of stressors. They compete for food, risk getting eaten by a predator, suffer illness and must contend with extreme weather conditions. And as if life in the wild wasn't hard enough, humans are now adding additional stressors such as chemical, light and sound pollution, as well as habitat destruction.

Given the widespread loss of biodiversity, understanding how animals react to and are harmed by these stressors can help conservation groups better protect them. But accounting for such a diversity of stressors is no easy feat. To address this need and demonstrate the cumulative impact of multiple stressors, our research team decided to develop an index for wild animals based on psychological research on human childhood trauma.

A cumulative adversity index

Developmental psychologists began to develop what psychologists now call the adverse childhood experiences score, which describes the amount of adversity a person experienced as a child. Briefly, this index adds up all the adverse events — including forms of neglect, abuse or other household dysfunction — an individual experienced during childhood into a single cumulative score.

This score can then be used to predict later-life health risks such as chronic health conditions, mental illness or even economic status. This approach has revolutionized many human health intervention programs by identifying at-risk children and adults, which allows for more targeted interventions and preventive efforts.

So, what about wild animals? Can we use a similar type of score or index to predict negative survival outcomes and identify at-risk individuals and populations?

Related: Why do some animals adopt other animals' young?

These are the questions we were interested in answering in our latest research paper. We developed a framework on how to create a cumulative adversity index — similar to the adverse childhood experiences score, but for populations of wild animals. We then used this index to gain insights about the survival and longevity of yellow-bellied marmots. In other words, we wanted to see whether we could use this index to estimate how long a marmot would live.

A marmot case study

Yellow-bellied marmots are a large ground squirrel closely related to groundhogs. Our research group has been studying these marmots in Colorado at the Rocky Mountain Biological Laboratory since 1962.

Yellow-bellied marmots are an excellent study system because they are diurnal, or active during the day, and they have an address. They live in burrows scattered across a small, defined geographical area called a colony. The size of the colony and the number of individuals that reside within varies greatly from year to year, but they are normally composed of matrilines, which means related females tend to remain within the natal colony, while male relatives move away to find a new colony.

Yellow-bellied marmots hibernate for most of the year, but they become active between April and September. During this active period, we observe each colony daily and regularly trap each individual in the population — that's over 200 unique individuals just in 2023. We then mark their backs with a distinct symbol and give them uniquely numbered ear tags so they can be later identified.

Although they can live up to 15 years, we have detailed information about the life experiences of individual marmots spanning almost 30 generations. They were the perfect test population for our cumulative adversity index.

Among the sources of adversity, we included ecological measures such as a late spring, a summer drought and high predator presence. We also included parental measures such as having an underweight or stressed mother, being born or weaned late, and losing their mother. The model also included demographic measures such as being born in a large litter or having many male siblings.

Importantly, we looked only at females, since they are the ones who tend to stay home. Therefore, some of the adversities listed are only applicable to females. For example, females born in litters with many males become masculinized, likely from the high testosterone levels in the mother's uterus. The females behave more like males, but this also reduces their life span and reproductive output. Therefore, having many male siblings is harmful to females, but maybe not to males.

So, does our index, or the number of adverse events a marmot experienced early on, explain differences in marmot survival? We found that, yes, it does.

Experiencing even just one adversity event before age 2 nearly halved an adult marmot's odds of survival, regardless of the type of adversity they experienced. This is the first record of lasting negative consequences from losing a mother in this species.

So what?

Our study isn't the only one of its kind. A few other studies have used an index similar to the human adverse childhood experiences score with wild primates and hyenas, with largely similar results. We are interested in broadening this framework so that other researchers can adopt it for the species they study.

A better understanding of how animals can or cannot cope with multiple sources of adversity can inform wildlife conservation and management practices. For example, an index like ours could help identify at-risk populations that require a more immediate conservation action.

Instead of tackling the one stressor that seems to have the greatest effect on a species, this approach could help managers consider how best to reduce the total number of stressors a species experiences.

For example, changing weather patterns driven by global heating trends may create new stressors that a wildlife manager can't address. But it might be possible to reduce how many times these animals have to interact with people during key times of the year by closing trails, or providing extra food to replace the food they lose from harsh weather.

While this index is still in early development, it could one day help researchers ask new questions about how animals adapt to stress in the wild.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Brain stimulation is an evidence-backed treatment for depression — and now, a clinical trial supports the idea that patients could do it themselves at home.

The trial showed that, under remote supervision, 87 patients with depression could successfully use a headset that delivers a weak electric current to a specific part of the brain. This kind of treatment, known as transcranial direct current stimulation (tDCS), would normally be given in a clinic.

After regularly using the headset for almost three months, these patients showed significantly greater improvement in their symptoms compared to a comparison group of 87 patients who followed the same procedure but with headsets that didn't deliver any electric current.

The findings, published Monday (Oct. 21) in the journal Nature Medicine, demonstrate that this approach could be a potential first-line treatment for depression, Dr. Cynthia Fu, study co-author and a professor of affective neuroscience and psychotherapy at King's College London, told Live Science. (Fu and colleagues received funding for the trial from the company that developed the device.)

However, experts not involved with the research told Live Science that issues with the trial's design could limit how well the research applies to people with depression, at large.

Related: 6 distinct forms of depression identified by AI in brain study

Around one-third of patients with depression still fail to see an improvement in their symptoms with first-line treatments, such as antidepressant drugs. Because of this, there's a demand for alternative therapies for the disorder, such as tDCS.

During a typical tDCS session in a clinic, a flexible cap or band fitted with electrodes is placed on a patients' scalp. A mild electric current is then applied through the electrodes to specific regions of the brain, most commonly the prefrontal cortex. This part of the brain is found just behind the forehead and its function is known to be impaired in depression. The electrical current tDCS delivers to the prefrontal cortex is thought to make it easier for neurons to fire, or to send signals to each other. Typically, patients come in for daily sessions for several weeks.

Previous clinical trials have suggested that tDCS could feasibly be used by patients at home under remote clinical supervision, like a video call. However, these trials have produced inconclusive results about how well at-home tDCS relieves symptoms.

In the new trial, Fu and colleagues developed their own version of an at-home tDCS device. They enrolled 174 patients in the U.S. and the U.K. who were in a depressive episode of "moderate severity." In this case, this meant each patient scored more than 17 on the Hamilton Depression Rating Scale (HDRS), a standardardized scale that clinicians use to measure the severity of a patients' depressive symptoms.

The researchers split the cohort in two. One half — the "active" treatment group — was instructed to use the headset at home in 30-minute sessions, repeated several times a week for 10 weeks. The control group also did this, but their headsets didn't deliver any stimulation. Both groups were guided by a doctor via videoconference.

Over the 10 weeks, both groups saw significant improvements in their depressive symptoms. HDRS scores improved by an average of 9.41 for the active treatment group and 7.14 for the control group. A significantly greater percentage of patients in the treatment group achieved clinical remission — about 45% compared to 22% of the control group. Remission means that a patient no longer has depressive symptoms.

Overall, 13 patients in the active treatment group and 12 in the control group discontinued treatment.

Limits to the research

While these results appear encouraging, there were several limitations of the trial.

For example, many patients correctly guessed whether they received tDCS or not, said Jonathan Roiser, a professor of neuroscience and mental health at University College London who was not involved in the research. This was probably because of minor side effects that can occur with tDSC, such as skin redness, Roiser told Live Science in an email. This may have potentially biased the findings because patients who knew they got the real treatment might have an inflated sense of how much their symptoms are improving.

Furthermore, the researchers noted in their paper that the study population mainly included white people, Dr. Sarah Lisanby, director of the Division of Translational Research at the National Institute of Mental Health who was not involved in the research. It's therefore uncertain if the same treatment would work for all demographics, she said.

The study also excluded patients with more severe forms of depression, which may also limit how well the findings apply to people with worse symptoms, she said.

Despite these constraints, the findings of the trial are still valuable, Lisanby said.

"Anything that we as a field can do to improve access to safe and effective mental health care is worth studying," she said.

This article is for informational purposes only and is not meant to offer medical advice.

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

New brain scans may help unravel a fundamental mystery about how our memory works on a day-to-day basis.

Similar to how a movie is divided into scenes, our brains organize our memories of each day into segments — separating when we went out to lunch from when we came home from work, for instance. But in movies, directors and editors decide when one scene ends and a new one begins. So how does the brain choose?

In theory, shifts in our environment may dictate when we've "entered a new scene," or instead, the brain may somehow determine the boundary between scenes.

Now, in a paper published Oct. 3 in the journal Current Biology, researchers found that the latter theory is likely correct — and that we may have more control over how we interpret the day's events than scientists previously thought.

Related: Sherlock Holmes' famous memory trick really works

Senior study author Christopher Baldassano, an associate professor of psychology at Columbia University, and his team wanted to understand what leads the brain to form boundaries around daily events, essentially changing from one "scene" to another. The leading theory has been that these boundaries are raised by a major change in the environment, such as when you walk into a movie theater or enter a grocery store, going from outside to inside.

However, another hypothesis suggests that these boundaries are created by our own past experiences and feelings about certain events or environments. So, while a change in environment can affect the segmentation of someone's day, it's possible that this influence can be overridden by our own priorities and goals.

To explore these hypotheses, Baldassano and his team created 16 short audio narratives. Each narrative involved four locations: a restaurant, a lecture hall, a grocery store and a restaurant. They also included four social situations: a business deal, a "meet-cute," a proposal and a breakup.

Volunteers listened to these narratives like podcasts while the scientists used functional magnetic resonance imaging (fMRI) to scan the participants' brains. Using a special method that the team had developed previously, they tracked changes in brain activity, especially in the medial prefrontal cortex (mPFC), part of the brain that perceives and interprets moment-to-moment input from our surroundings.

"We now had a tool where we could figure out what these dynamics look like and how people are dividing up these experiences," Baldassano told Live Science. They were able to track when a participant formed a new boundary during the narrative.

mPFC activity spiked when the key social events in the storyline changed — when the business deal was closed or the marriage proposal was accepted. However, if the team told participants to focus on features of the locations instead — such as sitting down at a restaurant and ordering food — their segmentation of the events changed, as did their brain activity.

The study also revealed differences in how the volunteers remembered the narratives after hearing them. When the participants were asked to recall the part of the story they were not asked to pay attention to, they forgot many details.

Related: The brain stores at least 3 copies of every memory

"You could view that as a good or a bad thing, in the sense that depending on the frame of mind you go into things with, it really does change your memory of what actually happened," Baldassano said.

Overall, though, "these results are exciting because they reveal how flexible and active our memory can be," said David Clewett, an assistant professor of cognitive psychology at UCLA who was not involved in the study. "Instead, we can choose what we pay attention to and what we remember. This means that, in many ways, we control the narrative of our own experiences," Clewett told Live Science in an email.

Difficulties with event segmentation is also common with certain conditions, such as post-traumatic stress disorder and dementia, as well as in normal aging.

The study suggests "memory-based treatments shouldn't just focus on any shift in a narrative to improve long-term memory," Clewett said. "Attention should be directed toward key moments — those that truly capture the essence and structure of an experience — to help people better understand and remember what matters most."

The researchers now hope to probe how long-term memory is affected by consciously shifting your attention as you divide the day into scenes.

"If you allow people to freely respond about what they remember," Baldassano wondered, "to what extent does this [shift in focus] change the way that they either frame the story or the kind of details they include?"

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

Have you ever taken a personality test? If you're like me, you've consulted BuzzFeed and you know exactly which Taylor Swift song "perfectly matches your vibe."

It might be obvious that internet quizzes are not scientific, but many of the seemingly serious personality tests used to guide educational and career choices are also not supported by research. Despite being a billion-dollar industry, commercial personality testing used by schools and corporations to funnel people into their ideal roles do not predict career success.

Beyond their lack of scientific support, the most popular approaches to understanding personality are problematic because they assume your traits are static – that is, you're stuck with the personality you're born with. But modern personality science studies find that traits can and do change over time.

In addition to watching my own personality change over time from messy and lazy to off the charts in conscientiousness, I'm also a personality change researcher and clinical psychologist. My research confirms what I saw in my own development and in my patients: People can intentionally shape the traits they need to be successful in the lives they want. That's contrary to the popular belief that your personality type places you in a box, dictating that you choose partners, activities and careers according to your traits.

What personality is and isn't

According to psychologists, personality is your characteristic way of thinking, feeling and behaving.

Are you a person who tends to think about situations in your life more pessimistically, or are you a glass-half-full kind of person?

Do you tend to get angry when someone cuts you off in traffic, or are you more likely to give them the benefit of the doubt – maybe they're rushing to the hospital?

Do you wait until the last minute to complete tasks, or do you plan ahead?

You can think of personality as a collection of labels that summarize your responses to questions like these. Depending on your answers, you might be labeled as optimistic, empathetic or dependable.

Research suggests that all these descriptive labels can be summarized into five overarching traits – what psychologists creatively refer to as the "Big Five."

As early as the 1930s, psychologists literally combed through a dictionary to pull out all the words that describe human nature and sorted them in categories with similar themes. For example, they grouped words like "kind," "thoughtful" and "friendly" together. They found that thousands of words could be accounted for by sorting them between five traits: neuroticism, extroversion, conscientiousness, agreeableness and openness.

What personality is not: People often feel protective about their personality — you may view it as the core of who you are. According to scientific definitions, however, personality is not your likes, dislikes or preferences. It's not your sense of humor. It's not your values or what you think is important in life.

In other words, shifting your Big Five traits does not change the core of who you are. It simply means learning to respond to situations in life with different thoughts, feelings and behaviors.

Can you change your personality?

Can personality change? Remember, personality is a person's characteristic way of thinking, feeling and behaving. And while it might sound hard to change personality, people change how they think, feel and behave all the time.

Suppose you're not super dependable. If you start to think "being on time shows others that I respect them," begin to feel pride when you arrive to brunch before your friends, and engage in new behaviors that increase your timeliness — such as getting up with an alarm, setting appointment reminders and so on — you are embodying the characteristics of a reliable person. If you maintain these changes to your thinking, emotions and behaviors over time — voila! — you are reliable. Personality: changed.

Data confirms this idea. In general, personality changes across a person's life span. As people age, they tend to experience fewer negative emotions and more positive ones, are more conscientious, place greater emphasis on positive relationships and are less judgmental of others.

There is variability here, though. Some people change a lot and some people hold pretty steady. Moreover, studies, including my own, that test whether personality interventions change traits over time find that people can speed up the process of personality change by making intentional tweaks to their thinking and behavior. These tweaks can lead to meaningful change in less than 20 weeks, instead of 20 years.

Cultivating personality traits that serve you best

The good news is that these cognitive-behavioral techniques are relatively simple, and you don't need to visit a therapist if that's not something you're into.

The first component involves changing your thinking patterns — this is the cognitive piece. You need to become aware of your thoughts to determine whether they're keeping you stuck acting in line with a particular trait. For example, if you find yourself thinking "people are only looking out for themselves," you are likely to act defensively around others.

The behavioral component involves becoming aware of your current action tendencies and testing out new responses. If you are defensive around other people, they will probably respond negatively to you. When they withdraw or snap at you, for example, it then confirms your belief that you can't trust others. By contrast, if you try behaving more openly — perhaps sharing with a co-worker that you're struggling with a task – you have the opportunity to see whether that changes the way others act toward you.

These cognitive-behavioral strategies are so effective for nudging personality because personality is simply your characteristic way of thinking and behaving. Consistently making changes to your perspective and actions can lead to lasting habits that ultimately result in crafting the personality you desire.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Dr. Dinesh Bhugra became interested in psychiatry while dissecting cadavers in medical school in Pune, India. From the inside, the bodies looked so similar, yet people think and behave so differently, he mused. He became fascinated with the forces that shape differences in behavior, eventually focusing on culture.

"Most of my active research has been on culture and mental illness," said Bhugra, who previously served as president of the Royal College of Psychiatrists, the World Psychiatric Association (WPA) and the British Medical Association.

Bhugra, who is also a professor emeritus of mental health and cultural diversity at the Institute of Psychiatry, Psychology and Neuroscience at King's College London, has spent much of his career striving to improve public mental health. He's addressed gender-based interpersonal violence and worked to reach underserved populations, including refugees, asylum seekers, elderly populations, and the LGBTQ+ community. Bhugra, the first openly gay president of the WPA, has also been outspoken on how prejudice and discriminatory policies impact the mental health and suicide rates of LGBTQ+ people.

Live Science spoke with Bhugra ahead of the HowTheLightGetsIn festival in London, where he will discuss mental health, how we define "normal behavior" and whether those definitions are actually useful benchmarks in the context of psychiatric care. His talk will take place Sept. 22.

Related: Newfound 'brain signature' linked to multiple psychiatric disorders

Nicoletta Lanese: You emphasize that psychiatry deals with a complex mix of biological, cultural and socioeconomic components. Do you feel like that concept is well incorporated into modern psychiatry?

Dr. Dinesh Bhugra: I think there are still gaps. Quite often as clinicians, we do not have enough time to explore everything. I've seen it in places like India, where the consultation is so short. So, you know, a patient starts speaking, you kind of give them a prescription — but it [psychiatric care] is much more than that.

What I've found in clinical practice is that most patients can live with their symptoms as long as they have a job, they've got some money in their pocket, they've got a relationship, they've got a roof over their head. As clinicians, we are focusing on symptom eradication or symptom management. So there is a tension there, which is much worse in some countries where resources are not adequate. I know colleagues in India who may see between 50, 100 patients a day, so you're giving five-minute consultations. Whereas in the U.S.A. and U.K. you probably get a bit more time, but often not enough [to really get to know a patient].

Something else which has been intriguing me in the last few years has been the notion of identity. We all have multiple micro-identities, and those are kind of a mosaic. Depending upon who you're talking to, bits of the identity light up — whether it's gender, religion, sexual orientation, profession. And quite often in clinical settings, we see the identity as that of "the patient," not an individual.

And I think that needs to shift. … It's incredibly important to see the individual as an individual rather than as a set of symptoms.

NL: I know you do a lot of work related to training the next generations of psychiatrists. I'm wondering what you see as a good way of helping them develop that cultural understanding?

DB: Firstly, everybody has a culture. And one of the things in cultural competency is understanding your own culture, its strengths and its weaknesses. And then, you know, looking at the individual … through that lens, to understand "Why are they feeling like this? Why are they expressing their distress in this way? Am I really understanding that?"

You can't be an expert in every culture, but [what's crucial is that] you're aware that this individual is different [from others even within their own culture and geographical setting].

Equally importantly, if you don't know something, be prepared to acknowledge that. "No, I don't know this, but I know somebody who might be able to educate, inform, teach me," whether it's community leaders or an individual's family. The family will tell you whether this person is behaving as "normal" or "abnormal." And that's the crux: how cultures define what is deviant, what is normal, what's acceptable.

NL: On that note, could you give us a preview of what you might talk about at the HowTheLightGetsIn festival?

DB: It's about "What's normal?" And again, from a cultural perspective, what's normal in one culture is not normal in another. Particularly from a psychiatric point of view, we need to be sensitive to those variations and variables. And it's also worth considering that what is normal today may not be normal in a year's time; what was normal 50 years ago may not be acceptable, may be seen as deviant now.

One of the examples that quite often I give in terms of cultural variations: In the U.S.A. post-Stonewall riots, in 1973 homosexuality was taken out of the diagnostic and statistical manual. So overnight, millions of people were "cured"; they did not have a mental illness anymore. So how do we as clinicians and researchers and the interested public make sense of those kinds of things which are sometimes imposed upon us — that this is "deviant," this is not acceptable.

Cultures influence cognitive development. Cultures influence the way we see the world. So we may be seeing the same mosaic from different angles. And part of the challenge is, how do we bring those two differing views together? Any definition of "normal" changes.

Particularly for psychiatric disorders that's even more relevant because we have few objective tests. So making sense of individual experience then becomes absolutely vital in the context of the family, community, culture, society, national and international norms.

Related: 'Fossil viruses' embedded in the human genome linked to psychiatric disorders

NL: In gaining that cultural understanding, how can psychiatrists-in-training recognize their own learned biases?

DB: I always start off by saying that, "Everybody has at least one prejudice." So the challenge really is, how do you know what it is and what are you going to do about it? That's the starting point in that dialogue about being aware of one's own biases, whether they're conscious or unconscious, whether they are visible or not.

One of the other things that I've been writing about quite a lot recently is the notion of "other" — we create "others" because that gives us our identity. I am not like you; I am different, you are different. How do we accept that difference? How do we make sure that I'm aware, whether it's a gender bias or religion bias or age bias or socioeconomic bias or skin color?

In clinical settings that's absolutely critical because we can then get into ridiculous stereotyping, which gives us a shortcut but it's problematic. No two patients who have similar symptoms will respond or explain [their experience] in the same way.

NL: What role do you feel psychiatry plays in confronting norms that may be bigoted or harmful? I'm thinking of the criminalization of homosexuality, for example.

DB: Psychiatry as a discipline and psychiatrists as professionals have a major role to advocate for our patients. Quite often, patients are not in a position, or may not have the capacity or ability to advocate for themselves. And we are privileged, both in terms of our professional experience, context, learning, but also as members of society [in that psychiatrists hold status and influence]. So we've got a dual role in that advocacy to the policy makers, to funders for research, funders for services. … We are well-placed to be advocates.

But it's really important for us to learn from other cultures as to how they're doing things differently, perhaps with better results. Perhaps doing it in the context of working across barriers — working with religious leaders, working with community leaders, working with teachers, and so on and so forth. So how do we learn from each other?

NL: Do you have any final thoughts you'd like to close on?

DB: I'm going to leave with two key messages. One is that mental health is an integral part of health and it should not be seen as something out there, somebody else's problem. We all need to look after our mental health and well-being so that we can look after our physical health, and vice versa.

The second take-home message really is that health cannot be seen in a silo, or in isolation. Education, employment, housing, justice, health, they're all interlinked. And across all the age ranges from childhood to older adulthood, there are external factors which will impinge upon our health, including mental health. And we need to be aware both from a policy perspective, but also from [the perspective of improving] prevention of mental illnesses and distress and promoting well-being and mental health.

Live Science has partnered with HowTheLightGetsIn festival, which takes place from Sept. 21 to 22 at Kenwood House in London. See how you can get a special discount.

The seventh season of Julia Child's "The French Chef," the first of the television series to air in color, revealed how color can change the experience of food. While Child had charmed audiences in black and white, seeing "Bouillabaisse à la Marseillaise" in color helped elevate the experience from merely entertaining to mouthwatering.

I am a psychologist who studies visual abilities. My work, through a serendipitous research journey into individual differences in food recognition, uncovered a unique role for color in emotional responses to food.

People vary in their ability to recognize food

This journey started when my students and I measured how people vary in their ability to recognize images of prepared food. Over the past 20 years, we and other researchers have learned that people vary more than originally suspected in how well they discriminate and identify objects, like birds, cars or even faces.

It seems obvious that some people know more than others about birds or cars. Yet, interestingly, there is as much variation in face recognition ability, even though virtually every sighted person has experience seeing faces.

Experience with food is also universal. We were curious how much people would vary in their ability to recognize food items. Our tests simply ask people to match images of the same dish among similar ones, or to find the oddball dish among others. People vary a great deal on these tasks, and some of this variation is explained by a general ability to recognize objects of any kind.

But a portion of the food recognition differences among people was not explained by this general ability. Instead, we speculated that this variability may be related to people's attitude toward new foods. People who strongly endorse statements like "I don't trust new foods" or "I am very particular about the foods I eat" have what's called food neophobia. It can lead to poor diet quality, resulting in nutritional deficiencies and higher risk of chronic disease.

As we predicted, we found that picky eaters scored worst on our tests of food recognition: Food neophobia is negatively correlated with food recognition ability.

Related: Why do we crave comfort food?

Color connects food neophobia to recognition

While we were publishing our results, other scientists were debating new findings about how the brain reacts to food and color. Different research groups had identified brain areas in the visual system that responded preferentially to images of food. For instance, looking at a bowl of pasta would activate these brain areas, but not looking at a pile of string.

The scientific disagreement was about what it meant to identify a selectivity for food in areas of the brain already known for their responsiveness to color.

One group proposed that these parts of the brain responded to color because they are specialized to recognize food. The other group argued that color was not critical to the brain's response to food. They even showed they could get similar brain activation when people looked at gray-scale images of food.

Was it possible that color was not critical to food recognition, while still playing a special role? We decided to replicate our initial study, with images of food in gray scale.

But we did find one effect of removing color: food neophobia was no longer correlated with food recognition ability. It was as if whatever advantage the adventurous eaters had gained over picky eaters was all dependent on color.

Based on these results, we proposed two separate components of food-specific recognition ability. One is independent of color and explains why the results are the same in the experiments with and without color. The other one, related to emotional responses, is based on color and evidenced by the finding that food neophobia is only related to food recognition when the food appears in color.

We then made an entirely new prediction: Would people with color blindness — men, really, because color blindness affects 16 times more men than women — be less food neophobic than those with normal color perception? Because someone who is colorblind experiences food in a restricted range of color, some of the signals that raise flags about freshness, safety or otherwise drive anxiety about novel food could be limited.

We recruited participants online, including men in our study based on how they answered one question about color blindness that was buried in a long screening questionnaire. Our participants had no idea that we were interested in color blindness when we asked them then to fill out the Food Neophobia Scale that measures how resistant people are to new foods.

We found that colorblind men were indeed less food neophobic than non-colorblind men. We replicated this finding in another study, with colorblind men also reporting lower levels of food disgust. Seeing the world with a restricted color palate seems to mitigate an emotion-based resistance to new foods.

Color and emotional responses to food

Our research is broadly consistent with other findings. Color can help you decide whether food is cooked or if produce is ripe or rotten, and people tend to prefer meals with a range of colorful foods. Other research shows that color can influence what food tastes like. Some biologists have argued that the coloration of plants and the ability of animals to detect it have co-evolved.

The role of color in emotional responses to food opens up new avenues for addressing extreme cases of food neophobia. As researchers learn more about the intricate relationship between color perception and food, we might develop targeted interventions to improve dietary habits. Just like Julia Child's colorful dishes, understanding and leveraging the power of color could enhance the appreciation and enjoyment of food.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

The old Latin adage "In vino veritas" — meaning "In wine, there is truth" — is just one of a litany of sayings perpetuating the idea that alcohol is a sort of truth serum. The phrase is attributed to Pliny the Elder, a Roman scientist, historian and soldier, though similar aphorisms can be traced back even further, to ancient Greece.

But does alcohol really make people more honest? The answer is both yes and no, experts told Live Science.

Alcohol "makes us more likely to say whatever's on our minds," said Aaron White, leader of the National Institute on Alcohol Abuse and Alcoholism's Epidemiology and Biometry Branch. "In some cases, that could be the truth. In some cases, it could be what you think is the truth in your intoxicated state."

So there's definitely a higher likelihood that someone will speak their mind after a few drinks. But there's also a chance that they will say something that feels real while drunk but that they wouldn't take seriously while sober. For example, a drunk friend might make bold promises they're going to move cities or quit their job only to take them back the next morning.

While an extensive online search didn't turn up any direct results for research on how alcohol influences honesty, studies about alcohol's impact on personality, emotion and cognition help support this idea.

For example, a 2017 study in the journal Clinical Psychological Science explored how participants' personalities changed after they'd consumed enough vodka lemonades to bring them to 0.09% blood alcohol concentration — just over the federal legal driving limit in the U.S. and England. Outside observers remarked that the biggest change in participants' personalities after drinking was that they became much more extroverted. Though the study didn't investigate whether alcohol was a truth serum, it makes sense that someone who feels more at ease in a social setting is also more likely to be candid.

Alcohol's ability to help people come out of their shell may help them say what's on their minds, but White says its effects on emotions can make those thoughts more mercurial.

Related: How a hangover affects your brain the next day

"We generally find that drinking alcohol tends to intensify our emotions," Michael Sayette, a professor of psychology at the University of Pittsburgh, told Live Science in an email. "We may find ourselves smiling more and speaking more loudly in pleasant interactions, but perhaps, as the researcher [professor emeritus at Stanford University] Claude Steele put it, we might also be more likely to cry in our beer in less-pleasant situations."

Those heightened emotions might lead people to say what's on their sober mind, but they can also put someone in a volatile state where they say something they don't really mean or deeply regret later. It's similar to how drinking makes some people more likely to become violent or to gamble — actions that may cross their sober minds, but they would have the wherewithal to avoid.

"Because alcohol can change our thoughts and feelings, it's unsurprising that behaviors can also change," Sayette said. "Alcohol can lead our behaviors to become more extreme."

These effects stem from alcohol's ability to cause disinhibition, which means a person is more likely to act on their impulses. This happens because alcohol dampens signals in the prefrontal cortex, a region of the brain that regulates behavior and controls impulses, White explained.

What's more, alcohol also suppresses the amygdala, a structure deep in the brain known for sparking feelings of fear and anxiety. While a person is sober, the amygdala generally sends out warning signals that can stop a person from saying or doing things that could lead to a social faux paus, but those signals quiet down after a few drinks.

So is there really "veritas in vino"?

Sure, people might be more likely to divulge secrets after a few glasses of wine — but they're also likely to blurt out something they don't really mean and will regret the next morning. The effects of alcohol on the mind are simply too complex to have a black-and-white effect on honesty.

"Alcohol is not a truth serum," White said. "That's for certain."

From rom-coms to romance novels, there's a common trope when it comes to love: opposites attract.

But is that really true? Actually, it's the opposite in real life: A slew of research over the past several decades has shown that people tend to date people who are more similar to themselves. People with shared traits are also more likely to have the long-term attraction needed for lasting relationships.

"When people talk about opposites attracting, that's thought of as being, 'Oh, I know this one couple; they got together, and they don't have a lot in common.' But it tends to be the exception to the rule," Erica Slotter, a psychologist at Villanova University in Pennsylvania, told Live Science. "Similarity is still a robust predictor of attraction."

In fact, similarity plays a key role in all stages of relationship formation. Researchers look into a person's stated preferences, or the attributes people say they look for in another person.

"Most of the time, people say they want people who are like them," Slotter said. This holds for all sorts of attributes, such as socioeconomic status, religion, political orientation and hobbies.

When looking at the data on people in longer term relationships, similarity also seems to reign supreme. Tanya Horwitz, a researcher at the University of Colorado Boulder, led a study on these trends by analyzing past literature and large-scale demographic datasets. The results, published in the journal Nature Human Behaviour in 2023, concluded that up to 89% of traits between partners were positively correlated, meaning if, say, one person exercised a lot, their partner was likely to as well. This held for politics, health habits, substance use and more. "We did the raw data analysis with the 133 traits," Horwitz said. "It was surprising just how uncommon it is to see a trend where people are less similar."

So does that mean you're destined for someone who is your carbon copy? Not exactly.

One trait that tends to be different between partners is how they take charge in social interactions, also known as social dominance. If both individuals in a pair are dominant, "they tend to butt heads," Slotter said. In contrast, two submissive, go-with-the-flow people may never deal with problems in a relationship. People with opposing social dominance tend to be happier than those with similar scores, Slotter added.

Two people who differ on paper may also be attracted to each other for another reason: chemistry. For instance, studies on speed dating have found that what we say we want in a partner doesn't always match up to who we're physically or emotionally attracted to. How this works is still a bit of a mystery. Slotter said that it’s partly because when we talk to someone face-to-face, we’re still looking for similarity but in a more holistic way. She added that increased holistic similarity is found to be linked to better romantic chemistry.

Even if they start out fairly different, partners can become more similar over time — a phenomenon called convergence, Horwitz said. Spending time together can shift things such as habits and lifestyle. This can also increase attraction as a relationship grows, Horwitz added.

Finally, who we think we are and our impressions of our partner may also affect lasting attraction. For example, a 2000 study in the Journal of Experimental Social Psychology found that it didn't matter whether strangers or friends thought individuals in a couple were similar. Instead, fondness, as well as relationship satisfaction, depended on whether the people in the relationship thought their partner was similar to them.

"It's really about that … subjective judgment you make," Slotter said. "If you feel like this person is similar to you, go for it. Because … that seems to matter the most."

Two astronauts marooned in space may sound like the plot of a Hollywood blockbuster, but for two NASA crew members, it is now a reality. Commander Barry Wilmore and pilot Sunita Williams are currently in limbo on the International Space Station (ISS).

They arrived in the Boeing Starliner spacecraft — the first test of the spaceship with astronauts. Wilmore and Williams were supposed to stay on the ISS for around eight days and return on the same spacecraft. But there is now debate about the safety of Starliner after it experienced helium leaks and thruster problems on its way to the ISS.

In coming days, Nasa and Boeing may decide to clear Starliner to carry the astronauts back to Earth. This means their stay might not last too much longer. But if officials decide against Starliner, the astronauts face waiting an additional six months in orbit before returning. So how do astronauts cope with a potential six-month wait for a lift home?

Waiting for things is difficult at the best of times. Under normal circumstances, it is frustrating, stressful and anxiety-provoking. But in extreme situations, with high stakes, waiting can be purgatory.

Part of the reason that waiting is difficult is that it distorts our sense of time. Think of last time you were waiting for a delayed train, test results or a text from a potential new partner. Did it fly by or drag? For most people, time spent waiting crawls at a glacial pace. As a result, delays and periods of anticipation often feel much longer than they actually are.

Waiting slows our perception of time, because it changes the amount of time that we spend thinking about time. During normal daily life we often ignore time; our brains have a limited capacity. If time isn't important, we simply don't think about it, and this helps it to pass quickly.

Related: Why time seems to fly by

When we are waiting, our desire to know when the wait is over increases how much we think about time. This "clock watching" can make the minutes and hours feel like they are passing at a snail's pace. Stress, discomfort and pain exacerbate this effect, meaning that waiting in difficult situations can seem even longer.

Waiting also slows our perception of time because it influences what we do and how we feel. Normal life is busy and full of ever-changing activities and interactions. The sudden need to wait halts the flow of life, often leaving us with nothing else to do, thus increasing levels of boredom and frustration.

In general, time filled with activity passes more quickly. We all got a taste of this during COVID lockdowns. When we were stuck inside unable to see friends and engage in normal daily activities, the loss of routine and distractions caused time to drag for many.

For the astronauts stuck on the ISS, anxiety about when they will return, limited opportunities for activities and fewer opportunities to contact friends and families combine to make their wait to return home feel significantly longer than six months — if it should come to that.

However, as academics who research the effects of time on human psychology and biology, our ongoing work with crew members at research stations in Antarctica aims to shed light on whether waiting in extreme environments is different to waiting during normal daily life.

A year in Antarctica

While being stuck for six months on the ISS may sound like many people's worst nightmare, it is not uncommon for scientists to spend long periods isolated and confined in extreme environments. Every year, organisations such as the Instituto Antártico Argentino (which uses the Belgrano II Antarctic station), the French Polar Institute and the Italian Antarctic Programme, in cooperation with the European Space Agency (which all use Antarctica's Concordia station), send crews of people for up to 16 months to conduct research on the frozen continent.

During the March to October polar winter, teams spend six months in near darkness — and from May to August, in complete darkness — facing outside temperatures of up to -60C, wind speeds of 160 km/h (100 mph) and storms which prevent almost all outdoor activity. Limited internet coverage can also prevent constant communication with the outside world.

For the last year, we have researched how life in Antarctica influences people's experience of time. Each month, we asked crew members how time felt like it was passing in comparison to before their mission. Trapped on base, with limited contact with the outside world, you might expect time to drag. However, our results suggest the opposite may be true.

Analysis of crew members' experiences indicated that being constantly busy with complex tasks such as scientific research helped time to pass swiftly, according to 80% of crew responses. Only 3% of responses indicated that time actually dragged, and these reports occurred when nights were long and there was little to do.

These experiences may provide hope for those stuck on the ISS. Like life on an Antarctic station, these Nasa astronauts have a busy and mentally demanding existence. These factors may help time to pass quickly.

However, a key factor of their wait may be their ability to tolerate the uncertainty of when they will return. Wilmore and Williams will spend their time in a space equivalent to the inside a Boeing 747 plane. But better information about "when" things will happen and "why" delays are being incurred can help people to tolerate waiting and reduce its impact on their wellbeing.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

"Look for the gap!" "Move into space!" "Who's free?"

Sound familiar?

From the sidelines to the field, court or pitch, no matter the team sport, looking for relevant information in the playing environment can be as important as any other skill if you want to score… and hopefully win the game.

Think Lionel Messi, Scott Pendlebury, or Natalie Medhurst, coolly assessing all the options before making pivotal decisions.

How do these elite athletes become so great? As well as their physical attributes, their brain power is an obvious asset.

Related: Will Olympic athletes ever stop breaking records?

Cognitive power in sport

Regardless of whether an athlete is playing under-5's soccer, backyard cricket or Olympic basketball, their playing environment holds important information that must be found, interpreted and then acted on.

As the athlete becomes more experienced with repeated game play, they become used to exploring the environment and the likely outcomes for different choices — such as in soccer, deciding on a long kick or a short pass.

This is how motor (movement) and cognitive expertise develops and can increase tactical and strategic options and solutions.

Cognitive expertise refers to factors such as decision-making, attention and perception, which are essential for skilled performance.

A key part of making decisions in sport, particularly fast-paced sports, is knowing where to look to find the most useful information around you. In other words, where you should direct your attention, particularly visual attention.

Research tends to find skilled players are better at looking for and seeing the options and what's happening around them in the playing environment.

For example, skilled players tend to have a wider focus of attention (when needed) — this means they look both at an opponent and where they can move to next.

Less skilled players, on the other hand, tend to have a narrower focus of attention. They might watch only one detail (such as the ball) but not what is happening around them.

An eye-tracking activity with soccer star Cristiano Ronaldo showcases this well:

Skilled players are also often faster to make decisions compared to less skilled players; their experiences create more stored memories that help speed up their decision-making.

In essence, skilled players know what information is the most relevant to focus on and they act on it quickly.

Related: What's the heaviest weight a person can lift?

Training the brain

Many in high performance environments acknowledge that we are near our physical limit with current practices.

Despite this, many coaches and athletes focus on the physical aspects of preparation such as speed, endurance and strength.

This focus is understandable — concentrating on physical aspects might work for sports that are driven largely by factors such as physical capacity and less by specific skills.

For sports like soccer, Australian rules football, hockey and basketball however, where complex thinking skills are needed, this approach is limited.

To put it simply: being able to move quickly and powerfully is helpful. But if you're running to the wrong spot, or kicking to a teammate in a bad position (overlooking a much better option), this lack of cognitive skill can limit success.

And there is more we can do with cognitive processes as our understanding continues to grow.

New research shows the importance of brain power

A recent study from Western Sydney University looked at Australian rules football players aged 14 to 18, and the skills they need to play at higher levels.

The researchers wanted to explore how junior players look around the field and make passing decisions, and if these behaviours stay the same over time (18 months, to be exact).

They found, similar to adult athletes, there are distinct differences for visual behaviors and decision-making abilities between skilled and less skilled juniors.

The more skilled players were more accurate in their decision-making and visual search behaviours, focusing on the most relevant game play information such as free players or space to move into.

Processing information under pressure is also key to skilled performance, with research showing physical fatigue affects decision-making, often leading to errors in decisions that can be costly.

For coaches, it is particularly important to consider cognition and fatigue in training — simulating game-like pressure is useful for players to get used to the types of pressures they will experience in competition.

Adding to this picture is new research that explores the negative impact of mental fatigue on physical performance. This work showed our ability to exercise can be impaired after activities requiring long periods of thinking and mental effort, particularly when these activities are boring.

This research is unique, as it considers the impact of using the brain so much that it makes you physically tired (often, we view fatigue from the perspective of how physical fatigue effects thinking).

This may be particularly relevant for coaches of young players transitioning from the school day to training, especially if the day's lessons have been complex.

Coaches should therefore consider the amount of information they provide athletes and the complexity of the tasks and instructions.

Related: 'Muscle memories' get 'zipped and unzipped' in the brain, like computer files

Striking the right balance at training

Overall, cognitive skills, like physical attributes, are key to high performance and even play a role in identifying future potential.

Developing talent in sports is a key focus for many sports clubs but the process relies mostly on testing physical and physiological aspects.

The research conducted at Western Sydney University showed cognition could be a reliable marker of ability over time and provide some basis for prediction of talent.

If so, the methods used or similar approaches could be included in talent identification protocols.

Simon Boas, who wrote a candid account of living with cancer, passed away on July 15 at the age of 47. In a recent BBC interview, the former aid worker told the reporter: "My pain is under control and I'm terribly happy — it sounds weird to say, but I'm as happy as I've ever been in my life."

It may seem odd that a person could be happy as the end draws near, but in my experience as a clinical psychologist working with people at the end of their lives, it's not that uncommon.

There is quite a lot of research suggesting that fear of death is at the unconscious centre of being human. William James, an American philosopher, called the knowledge that we must die "the worm at the core" of the human condition.

But a study in Psychological Science shows that people nearing death use more positive language to describe their experience than those who just imagine death. This suggests that the experience of dying is more pleasant — or, at least, less unpleasant — than we might picture it.

In the BBC interview, Boas shared some of the insights that helped him come to accept his situation. He mentioned the importance of enjoying life and prioritizing meaningful experiences, suggesting that acknowledging death can enhance our appreciation for life.

Despite the pain and difficulties, Boas seemed cheerful, hoping his attitude would support his wife and parents during the difficult times ahead.

Related: What is the key to happiness? We look at the science behind it.

Boas's words echo the Roman philosopher Seneca who advised that: "To have lived long enough depends neither upon our years nor upon our days, but upon our minds."

A more recent thinker expressing similar sentiments is the psychiatrist Viktor Frankl who, after surviving Auschwitz, wrote Man's Search for Meaning (1946) in which he lay the groundwork for a form of existential psychotherapy, with the focus of discovering meaning in any kind of circumstance. Its most recent adaptation is meaning-centered psychotherapy, which offers people with cancer a way to improve their sense of meaning.

How happiness and meaning relate

In two recent studies, in Palliative and Supportive Care and the American Journal of Hospice and Palliative Care, people approaching death were asked what constitutes happiness for them. Common themes in both studies were social connections, enjoying simple pleasures such as being in nature, having a positive mindset and a general shift in focus from seeking pleasure to finding meaning and fulfillment as their illness progressed.

In my work as a clinical psychologist, I sometimes meet people who have — or eventually arrive at — a similar outlook on life as Boas. One person especially comes to mind — let's call him Johan.

The first time I met Johan, he came to the clinic by himself, with a slight limp. We talked about life, about interests, relationships and meaning. Johan appeared to be lucid, clear and articulate.

The second time, he came with crutches. One foot had begun to lag and he couldn't trust his balance. He said it was frustrating to lose control of his foot, but still hoped to cycle around Mont Blanc.

When I asked him what his concerns were, he burst into tears. He said: "That I won't get to celebrate my birthday next month." We sat quietly for a while and took in the situation. It wasn't the moment of death itself that weighed on him the most, it was all the things he wouldn't be able to do again.

Johan arrived at our third meeting supported by a friend, no longer able to grip the crutches. He told me that he had been watching films of him cycling with his friends. He had concluded that he could watch YouTube videos of others cycling around Mont Blanc. He had even ordered a new, expensive mountain bike. "I've wanted to buy it for a long time, but was tightfisted," he said. "I may not be able to ride it, but thought it would be cool to have in the living room."

For the fourth visit, he arrived in a wheelchair. It turned out to be the last time we met. The bike had arrived; he had it next to the couch. There was one more thing he wanted to do.

"If by some miracle I were to get out of this alive, I would like to volunteer in domestic care services — one or two shifts a week," Johan said. "They work hard and it gets crazy sometimes, but they make such an incredible contribution. I wouldn't have been able to get out of the apartment without them."

My experience of patients with life-threatening disease is that it's possible to feel happiness alongside sadness, and other seemingly conflicting emotions. Over a day, patients can feel gratitude, remorse, longing, anger, guilt and relief — sometimes all at once. Facing the limits of existence can add perspective and help a person appreciate life more than ever.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

A makeup brush swirling around a microphone, scissors gently snipping through thread, a person softly whispering — a search for "ASMR videos" turns up these and many more alluring sounds, and the catalog of videos has only grown since the phenomenon took the internet by storm in the 2010s.

But what, exactly, is ASMR, and how does it work? And can everyone experience ASMR?

ASMR stands for "autonomous sensory meridian response." Coined in 2010 by Jennifer Allen, who later founded online forums for ASMR, the term refers to a spontaneous, or automatic, sensation that's triggered by some stimulus and crescendos to a peak.

The phenomenon itself has different meanings for different people, said Giulia Poerio, a psychologist at the University of Sussex in the United Kingdom. But most researchers and listeners agree that ASMR has two major components: a tingly or "sparkly" sensation that begins in the head and then spreads down the spine, and a sense of euphoria and relaxation.

"It's kind of like having your hair stroked," Poerio told Live Science. Alternatively, ASMR feels a little like the chills that some people experience when listening to music, she said. But while music-induced chills can make your heart beat faster and your hair stand on end, ASMR tends to lower a person's heart rate and slow their breathing.

Related: What causes tinnitus, and can it be treated?

People experience ASMR in response to triggers, which can take lots of forms. "ASMRtists" who whisper into and tap their fingers upon microphones are particularly popular on YouTube. But in addition to auditory stimuli, tactile sensations, such as someone gently brushing your hair, can trigger ASMR, according to Poerio.

A whispery video or a comforting touch isn't enough to trigger ASMR on its own, though; people typically need to feel calm and safe in their environment for the sensation to materialize, said Craig Richard, a physiologist at Shenandoah University in Virginia and founder of ASMR University, an informational website.

ASMR content creators sometimes achieve this by creating a sense of familiarity with their audiences, said Richard, who also has a book and podcast about ASMR. In a 2018 study, Richard and colleagues proposed that many ASMR triggers are related to "affiliative behaviors," meaning caring behaviors exchanged between people with close interpersonal bonds, such as friends, parents and children, and romantic partners.

"If you look at almost any major, top ASMR video, it's someone pretending that they know you really well," Richard told Live Science. "It's sort of tricking your brain into thinking someone you know and are comfortable with is giving you positive personal attention."

A mix of neurotransmitters — chemical messengers of the nervous system — could be behind the phenomenon, Richard said, although researchers are still working to confirm the exact mechanism by which ASMR works.

In the 2018 study, the scientists found that certain regions of the brain become more active when people experience ASMR. They showed this using functional MRI scans, which indirectly measure brain activity by looking at blood flow through the organ.

Related: How do brain cells send messages?

Part of the brain called the medial prefrontal cortex (mPFC) lit up when people experienced relaxing or tingling sensations while watching ASMR videos. The mPFC is involved in myriad functions, including processing and directing social behaviors such as grooming. This might explain why gentle touches and caring interactions are common ASMR triggers. Oxytocin, a neurotransmitter and hormone associated with relaxation and social bonding, binds to receptors in the mPFC and could thus be involved in the relaxation that ASMR delivers.

Another part of the brain called the nucleus accumbens also lit up when study participants experienced brain tingles. This brain region helps direct motivated behaviors driven by reward and satisfaction, and it activates when people experience music-induced chills. Although ASMR and music chills don't feel quite the same, they might come about through a similar pathway, Richards and his co-authors theorized.

Not everyone experiences ASMR, and scientists are still trying to understand why.

"There's probably a neural basis to it, in terms of how your brain forms and your experiences in earlier development," Poerio said. Some studies have found that people with certain personality traits, such as neuroticism or openness to new experiences, are more likely to experience ASMR than those without these traits.

For some, though, it may be that they simply haven't yet found the right trigger for ASMR.

"Some will say that it's taken them 100 ASMR videos to find the type of trigger that works for them," Richard said. Then again, some people never experience ASMR from watching videos, he noted, but something in the real world might trigger the sensation.

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

Over the past decade, virtual assistants powered by artificial intelligence, like Apple’s Siri and Amazon's Alexa, have become integral to technologies such as smartphones and social media.

More recently, a new type of human-like chatbots are on the rise: AI romantic companions. Chatbots are AI-powered programs that engage with humans through text, voice and images.

Currently, over 100 AI-powered applications — such as myanima.ai, Eva AI, Nomi.AI and Replika — offer romantic and sexual companions with extensive personalization options, including physical and personality features. Exhibiting remarkable realism, adaptability and interactive fluidity, these AI chatbots can progressively evolve through conversation, fine-tuning their responses to match users' interests, needs and communication styles.

Modern AI chatbots have increasingly human-like qualities that raise users' propensity to engage and form emotional bonds — even to the point of falling in love.

RELATED: OpenAI unveils huge upgrade to ChatGPT that makes it more eerily human than ever

Exacerbated by COVID-19 pandemic restrictions, loneliness has led more people to use AI as a substitute for counselors, friends and romantic partners.

Romantic partner substitutes

Research shows AI chatbots can offer companionship, ease loneliness and boost positive emotions with supportive messages. Chatbots also provide a judgment-free space for open conversations and advice when other resources are scarce. People can also form intimate and passionate connections with AI that are similar to human relationships.

Surprisingly, there doesn't seem to be a difference in enjoyment, sexual arousal and emotional response whether participants believe they are interacting with a human or a chatbot. One study even showed that individuals feel a stronger emotional connection with chatbots compared to less responsive humans during a conversation.

Research repeatedly suggests that humans can form genuine emotional bonds with AI, even if they acknowledge it is not a "real" person. Although many people appear to derive psychological benefits from using chatbots, the potentially harmful consequences of these relationships remain unclear.

Dark side of AI love

Romantic chatbots are programmed to offer a unique form of companionship, with constant availability and seamless interactions while avoiding conflict and the need for compromise. This raises concerns about the impact on users’ expectations regarding human romantic and sexual relationships.

Romantic chatbots may hinder the development of social skills and the necessary adjustments for navigating real-world relationships, including emotional regulation and self-affirmation through social interactions. Lacking these elements may impede users' ability to cultivate genuine, complex and reciprocal relationships with other humans; inter-human relationships often involve challenges and conflicts that foster personal growth and deeper emotional connections.

The customizable nature and constant availability of AI companions can also lead to social isolation and emotional dependency. Researchers suggest that extensive engagement with AI companions might cause individuals to withdraw from their immediate environment and reduce their motivation to build new, meaningful social connections. Users may also come to overly rely on these digital entities for emotional support, companionship or sexual need fulfilment.

A notable example occurred in 2023 when Replika removed the sexual roleplay capabilities of its AI companions. This change significantly altered the personalities of existing Replikas, causing considerable user distress. Many users felt betrayed and rejected, and reported a profound sense of loss. Due to the outcry, Replika quickly reinstated the functionality for existing users.

Intimate surveillance

In 2023, a Mozilla Foundation security analysis of 11 popular AI chatbot apps uncovered alarming privacy issues. Most apps could share or sell personal data, with half preventing users from deleting their information.

Even more concerning is that many of these apps are packed with thousands of trackers that monitor user activity on their devices for marketing purposes. Another recent study on 21 AI romantic companionship apps revealed similar privacy concerns.

Enhancing romantic well-being

Although empirical data is still emerging, AI-driven sexual interactions could offer a safe, low-risk alternative to sexual and romantic relationships. Romantic and sexual chatbots hold particular promise for individuals experiencing major challenges in establishing satisfying romantic relationships due to illness, bereavement, sexual difficulties, psychological barriers or mobility impairments.

AI technologies could also be leveraged for sexual and romantic exploration among marginalized communities or among individuals that are socially isolated.

Additionally, chatbots can be used as a romantic socialization and research tool, helping individuals create bonds and improve their interactional skills. For example, research has shown their effectiveness in enhancing emotional communication among long-distance couples, while ongoing studies are exploring their potential to help individuals manage distress from being ghosted on dating apps.

As researchers at EROSS lab, located at the Université du Québec à Montréal, one of our ongoing studies assesses the use of chatbots to help involuntary celibates improve their romantic skills and cope with rejection.

Despite promising clinical applications, current sex research on the use of chatbots mainly focuses on sexual health education, covering topics like sexually transmitted infections and reproductive health.

Relationship revolution

Current advances in AI technologies are marking a new era for intimate romantic and sexual relationships. AI chatbots can offer personalized romantic and emotional fulfilling interactions, with promising opportunities to alleviate loneliness, enhance romantic skills and provide support to those struggling with intimacy.

However, they also raise privacy issues and important ethical concerns that underscore the need for an educated, research-informed and well-regulated approach for positive integration into our romantic lives. But current trends indicate that AI companions are here to stay.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

The human body continues to surprise doctors, who report meeting patients with rare conditions or unique abilities. In this list, we take a look at 32 unusual medical cases reported throughout the years, zooming in on the patients' symptoms and outcomes. 

Not all of the cases are fully explainable, but in many of them, doctors determined the causes of the unusual conditions. A prompt diagnosis followed by the appropriate treatment meant a number of patients in these stories recovered, but some of the cases were fatal.

Cement in a man's heart

A 4-inch (10 centimeters) piece of cement got lodged in the heart of a 56-year-old man after traveling through his bloodstream after a surgical procedure.

The man was admitted to the emergency room after experiencing chest pain and trouble breathing for two days. An X-ray and CT scan confirmed that a foreign object was in his heart. During surgery, doctors found the object, which turned out to be a sharp, thin piece of cement that had torn through the upper-right chamber of the man's heart and punctured his right lung.

The cement had come from a procedure the man had a week earlier to treat a broken vertebra. Doctors injected a special type of cement to restore his vertebra. Although this procedure is usually safe, in this case, the cement leaked from the bone into the patient's veins. The cement then hardened and traveled through the man's bloodstream to his heart. He recovered a month after the surgery to remove the cement.

Green "furry" tongue

A man found that his tongue was sprouting green "hairs" after he developed a benign condition known as hairy tongue. Lingua villosa, as it is also called, happens when the tiny bumps on the tongue, called papillae, don't shed as they normally would and thus grow beyond their normal length, which is usually around 0.04 inch (1 millimeter) long. As the bumps grow, they turn a particular color — typically green, brown, white, green or pink — depending on the food, bacteria and other material they encounter.

The condition is fairly common, affecting about 13% of people at some point in their lives. Eating soft foods and drinking large amounts of coffee, tea or alcohol can increase the risk of developing hairy tongue. The 64-year-old in this case followed his doctors' instructions to scrub his tongue daily with a toothbrush, and his tongue turned back to normal in six months, the case report noted.

Fetus in a toddler's brain

Doctors surgically removed a fetus that was found in the brain of a 1-year-old girl. 

This rare condition, called intraventricular fetus in fetu, was discovered after the child developed an enlarged head and had delayed motor skill development. The fetus came from the same fertilized egg as the girl, so if the fetus had developed normally, it would have been her identical twin. However, when one fetus envelops the other, the absorbed twin typically stops developing.

Fetus-in-fetu is very rare, occurring in only about 1 in 500,000 births. Most cases of the phenomenon happen in the abdomen, rather than the head. 

Student able to change pupil size

Most of us can't tell what our pupils are doing, as usually, they automatically dilate in the dark to let in more light and constrict in bright environments to limit the amount of light that flows through them. However, one student in Germany found he could enlarge and shrink his pupils voluntarily.

The 23-year-old told researchers that constricting his pupils felt like tensing something, while making them larger felt like he was fully relaxing his eyes. At first, he changed his pupils' sizes by focusing in front of or behind an object, and then with practice, he learned how to do it simply by concentrating on his eyes. Although some people can achieve this effect indirectly, such as by thinking about the sun, researchers couldn't find any indication that the student was using such a method.

Man living normally with small brain

A 44-year-old man who worked as a civil servant was leading a normal life, despite his brain being at least half the average size.

This case was described in the journal The Lancet after the man sought medical help because he had felt weakness in his left leg for two weeks. When he was 6 months old, doctors had placed a shunt in his head to relieve fluid buildup in his brain. At age 14, he lost full control of his left leg but recovered it after the shunt was altered. His neurological development and the rest of his medical history were otherwise normal.

However, after he sought medical help for the weakness in his leg, brain scans showed several abnormalities. His condition caused a buildup of fluid in his skull, which left him with just a thin sheet of brain tissue, because the fluid left little room for brain tissue. Feeling returned to his leg after a new shunt was inserted to drain the excess fluid.

Teen speaking only in a foreign language

A 17-year-old in the Netherlands lost his ability to speak and understand Dutch for 24 hours after an orthopedic surgery. During this case of foreign language syndrome (FLS), he could communicate only in English, which he'd never spoken outside of a classroom.

According to the case report, it started when the teen went to the hospital for knee surgery following an incident during a soccer game. This was his first time being operated on and undergoing general anesthesia. When he woke up, he was confused and thought he was in the United States, specifically Utah. A psychiatrist confirmed that the teen could answer questions only in English — adequately but not fluently. 

When friends came to visit him around 24 hours after the surgery, the boy spontaneously began to understand and speak Dutch again. During a mental exam the next day, the teen said he could remember himself only speaking and understanding English. However, it could be that he thought this because he was told about the incident.

The authors of the case report believe this was the first scientifically reported case of FLS in a child or adolescent. It's unclear what caused the teen to experience FLS, but the authors hypothesized that it might have been linked to the anesthetic he was given. 

Severe side effect of holding in a sneeze

A man in his 30s was driving when he felt the urge to sneeze. He stifled his sneezes by pinching his nose and closing his mouth but immediately felt severe neck pain. When he went to the ER, a CT scan of his neck and chest revealed a quarter-inch-long (half a centimeter) tear in his trachea, or windpipe.

Doctors decided against surgery, since the man's vital signs were otherwise normal. Nevertheless, the patient was kept under observation. Five weeks after he was discharged, a follow-up CT scan showed that his trachea had healed. 

"We suspect the trachea perforated due to a rapid build-up of pressure in the trachea while sneezing with a pinched nose and closed mouth," the care team wrote in the journal BMJ Case Reports. They advised people not to stifle sneezes in this way. 

Girl born with hair all over her body

Since birth, a 2-year-old girl had hair all over her body, except on her palms, soles, mouth, eyes and nose.

In a report of the case, doctors noted that the girl had no other complications related to the condition, known as congenital generalized hypertrichosis terminalis. The main reason she was brought in for medical attention was that her parents were alarmed by her physical appearance. Doctors assured her parents that the condition was benign and listed some hair-removal options for the child.

Allergy to water

In an extremely rare case, an 18-month-old was diagnosed with an allergy to water, known medically as aquagenic urticaria. Within just 15 seconds of coming into contact with water, she experienced severe skin reactions, including hives and rashes.

The exact cause of this condition remains unknown. Some theories suggest the hives could be caused by a substance that's dissolved in the water, such as chlorine, rather than the water itself, or that something on patients' skin produces a toxic substance when it touches water.

Baby's changing eye color

A 6-month-old's eyes turned from brown to a deep indigo blue after he was given the antiviral favipiravir to treat COVID-19. 

Favipiravir stops viruses from replicating their genetic material. Less than a day after the antiviral drug was given to the infant, his eyes started shining blue in the sunlight. A medical examination revealed a buildup of blue pigment in both of his corneas — the clear, outer part of the eye. Five days after the antiviral was stopped, the boy's eyes returned to their original brown.

The blue may have been caused by the buildup of fluorescent chemicals in the cornea as the drug was broken down by the body, the case report authors suggested.

The dancing plague

One of the greatest unsolved mysteries of public health is what caused the three-century-long "dancing plague" in Europe.

Starting in the 13th century, people in Germany, the Netherlands and Italy would reportedly gather in large crowds and dance frantically until they got exhausted or died. As many as 1,100 people would take part in each gathering. There are detailed accounts of such dancing plagues in literature, but the exact cause remains unknown. It's likely that this dancing plague, or choreomania, was triggered by a combination of factors.

Historical accounts suggest that it was a mass psychological phenomenon triggered by social adversity and that it presented itself in the form of dancing due to the underlying culture of the period.

Fatal insomnia

A patient was sleeping only two to three hours a night in a case of fatal familial insomnia (FFI). The 57-year-old man had experienced progressive memory decline for one year before being admitted to the hospital. During the day, he often felt weak and often ended up falling asleep when he was sitting or lying down. His ability to use chopsticks worsened quickly, he developed issues walking soon afterward. The man died a few months after being admitted to the hospital.

FFI is a type of hereditary prion protein disease for which there's no effective treatment. Prion diseases occur when cells make dysfunctional proteins that accumulate in the brain, leading to progressive damage. The symptoms of FFI include insomnia, movement disorders and hormonal shifts. Tests usually reveal mutations in a gene called PRNP; one mutation called D178N is tied to both FFI and a second prion disease.

Police officer who recognized everyone

"Where do I know you from?" a police officer kept asking strangers. The 46-year-old had developed intermittent episodes of anxiety each lasting about 15 seconds; six months after these episodes began, he had a seizure. His MRI results and neurological exam were normal. However, a month after the seizure, he reported new symptoms. In addition to memory problems, he experienced an odd phenomenon: Every person he saw looked familiar.

A case report detailed how the officer's "hyperfamiliarity" also occurred to a lesser extent with faces in photos and on TV, but not with voices. Patients with hyperfamiliarity for faces (HFF) quickly realize that they're mistaken. They usually have lesions on the left hemisphere and temporal lobe of the brain, but the right hemisphere and frontal areas of their brains remain normal.

The left hemisphere is involved in identifying unique facial features, while the right is known to link  faces with emotional and personal meaning. Thus, HFF may occur when the left hemisphere is impaired and the right hemisphere overcompensates, leading to a false sense of familiarity. The authors of the report suggested that HFF is more common than suspected, since the vast majority of cases likely go unrecognized. 

Giant kidney worm

A young man went to the ER because he couldn't pee and he'd had a fever for two days. His vitals were normal except for a rapid heart rate. Hospital staff placed a catheter and gave the man IV fluids and a combination of drugs. But on his second day in the hospital, the patient found a worm in his urine bag. 

The hospital's microbiology department confirmed that the worm — which was red and almost 12 inches (30 cm) long — was the rare parasite Dioctophyma renale. When his urine was analyzed, no traces of the parasite's eggs were found. Although doctors advised against it, the man left the hospital after he had passed the worm.

D. renale is one of the largest known parasitic nematodes. It's found mostly in the kidneys of flesh-eating mammals, like dogs and wolves, which then excrete its eggs in their urine. Humans could get infected by eating raw or undercooked fish or frogs containing the larvae. In this particular case, the patient had eaten raw fish from a lake close to his home. It wasn't the first time he'd passed such worms. In complicated cases, the only treatment is for the infected kidney to be removed.

Related: 32 scary parasitic diseases

Child who ate "everything except food"

In a case report, doctors described how a 7-year-old girl reported to their department with a history of abdominal pain for three years, worn down teeth and cavities. The girl had been eating pieces of bricks for five years, despite warnings from her parents. 

It's common for babies to go through a temporary period of putting all kinds of things in their mouths. However, when a child past this phase starts eating things that aren't food again, there's cause for concern. When people start eating nonfood items such as stones, bricks, chalk and soap, the condition is known as pica. Possible causes of pica include iron deficiency and lead exposure. 

The child in the case report was given iron, zinc and calcium supplements, and her habit stopped after six months. 

Double teeth

When a 14-year-old boy went in for a routine dental checkup, dentists found that his left first premolar had two crowns. He had no symptoms related to the tooth and did not want any treatment for it, according to the report of the case.

Tooth gemination, commonly known as "double teeth," is a development disorder of a tooth's shape coming from a single tooth germ's unsuccessful attempt to divide. The exact cause of gemination is unknown, but environmental factors such as trauma or vitamin deficiencies may play a role.

Mermaid syndrome

A report describes the case of a baby with sirenomelia, also known as "mermaid syndrome," a condition in which a baby is born with a single middle lower limb instead of two legs. The baby was born with fused lower limbs and fused feet, which were rotated and aligned abnormally, making them resemble fins. The baby was transferred to a neonatal unit but died after seven hours of life.

Risk factors for mermaid syndrome include maternal diabetes and drug abuse, but the exact cause remains unknown.

Woman who couldn't feel pain

A 58-year-old woman had a long history of insensitivity to pain and recalled how, as a child, she would get cuts that she could not feel. She also did not feel pain when touching extremely hot or cold water, although she could tell the difference between the two, her doctors described in a case report. The woman, who has two children, didn't feel pain during childbirth, either.

She was diagnosed with a condition called congenital insensitivity to pain (CIP), a rare disease caused by mutations in the SCN9A gene. People who have CIP can feel different sensations but can't perceive pain.

Similar to others with CIP, the woman had anosmia, meaning she couldn't smell.

Persistent hiccups

While hiccups usually end on their own after a short while, that's not always the case. In fact, almost 4,000 people are admitted to the hospital in the United States for hiccups every year. 

A 22-year-old male reported having hiccups all day for two years. Past medical treatments, which were not described in the report, did not help. Due to his chronic hiccups, he quit his job and his social life broke down. He also started feeling abdominal pain and had anemia.

Eventually, he chose to undergo surgery to treat his gastroesophageal reflux, which was thought to be causing the hiccups, and he hiccuped throughout the procedure. Although the frequency of his hiccups decreased after the surgery, he wasn't entirely cured. While it's often not possible to identify a single cause for chronic hiccups, some cases include gastroesophageal reflux disease and adrenal insufficiency. 

Giant, lung-shaped blood clot

A man was admitted to the intensive care unit when his symptoms of chronic heart failure suddenly worsened. After admission he started coughing up blood and also had trouble breathing. He was given blood-thinning medication, which increased his risk of bleeding, for the serious heart condition. At one point, he started coughing violently — and he hacked up a giant blood clot in the shape of part of his lung. Basically, it was a mold of clotted blood in the shape of a branched airway called a bronchial tree. 

The 36-year-old man died a week later due to complications of heart failure. Doctors published the image of the blood clot in a case report in The New England Journal of Medicine.

Navy-blue blood

One night, a 25-year-old woman in Rhode Island applied large amounts of numbing medication to a tooth that was hurting her. The next day, she went to the ER because she felt weak and fatigued, was experiencing shortness of breath and had skin discoloration.

When her blood was drawn, it appeared a deep, navy blue instead of red. According to the case report, the woman had a condition called methemoglobinemia, where there's an increased level of a type of hemoglobin called methemoglobin, which, unlike the regular form of hemoglobin, can't carry oxygen to the rest of the body. 

The condition can be either congenital or a side effect of some drugs, including some anesthetics. The woman was quickly treated with intravenous methylene blue, which improved her breathing and reduced her skin discoloration. The medication helped by restoring iron to its proper form within her blood, and in this case, the woman made a complete recovery.

Beer-making belly

A man was arrested for "drunk driving" even though he insisted he hadn't been drinking. After this incident, he went to an Ohio clinic, where doctors found strains of Saccharomyces boulardii and Saccharomyces cerevisiae, known as brewer's yeast, in his stool samples.

It turned out that the man had a condition called auto-brewery syndrome, in which microbes in the gut transform carbohydrates into alcohol, according to a case report in the journal BMJ Open Gastroenterology. This diagnosis also explained why he had episodes of mysterious drunkenness and "brain fog." The man was cured after doctors placed him on antifungal agents and a carbohydrate-free diet for six weeks.

Sudoku-triggered seizures

In a puzzling case, a German man developed seizures while trying to solve a Sudoku brainteaser.

According to the report of the man's case, he hadn't always reacted this way to Sudoku. During a ski trip in 2008, he was buried in the snow by an avalanche, knocked unconscious and then given CPR. The man survived, but because his brain was deprived of oxygen for 15 minutes, he developed muscle jerks in his mouth and legs. After being given anti-epileptic medication, he started to recover.  

But while trying to solve a Sudoku puzzle at a rehabilitation facility, the man started experiencing involuntary jerking motions, called clonic seizures, in his left arm. Doctors later discovered that the seizures were triggered when the man imagined the numbers in Sudoku grids in three dimensions, which reportedly helped him solve the puzzles. Unfortunately, that put an end to the man's hobby, as it was the only way he could avoid the seizures.

Teeth in a baby's brain

A 4-month-old boy was taken for medical tests because his head appeared to be growing faster than what was normal for his age. A brain scan confirmed that he had a brain tumor. However, during brain surgery to remove the tumor, doctors found that it contained several fully formed teeth, according to the case report.

It turned out that the child had a craniopharyngioma, a rare type of benign brain tumor. After the surgery, his doctor said the boy was "doing extremely well, all things considered."

Long-lost contact lens found decades later

While playing badminton, a 14-year-old girl was hit in the eye with a shuttlecock. She was wearing a contact lens, which she couldn't find; she assumed it fell out of her eye and was lost. However, she was in for a surprise when she went to the doctor due to swelling in her left upper eyelid 28 years later.

An MRI showed a cyst, which was surgically removed. When it was removed, the cyst burst — and there, lo and behold, was the long-lost contact lens, her doctors explained. It turned out that during the badminton injury, the lens migrated to the woman's left upper eyelid, where it remained hidden for 28 years.

Baboon syndrome

Penicillin is one of the most commonly used antibiotics globally, but as with any other drug, it can have side effects. A 40-year-old man with a sore throat was given penicillin to treat tonsillitis. Days later, he developed a rash on his armpits, groin and buttocks in a case of "baboon syndrome," named after its resemblance to the red coloration on the rears of some monkeys.

The condition, formerly called "symmetrical drug-related intertriginous and flexural exanthema," is usually caused by an allergic reaction to penicillin or other substances, such as mercury. According to the man's case report, the rash disappeared after his medication was changed.

Temporary wrinkles

When a man put his hands in water, he developed "excessive wrinkling" on his hands that would disappear around 30 minutes after they dried, according to a case report in the journal JAMA Dermatology. 

The condition, called aquagenic syringeal acrokeratoderma (ASA), is a rare skin disease that usually occurs in young women, but in this instance, it affected a man in his 20s. It occurs mostly in people with cystic fibrosis.

The man sought medical help after experiencing the condition for three years, with the skin on his hands becoming swollen, wrinkly and scaly whenever they made contact with water. The man's palms were unaffected, which is unusual, but he was nonetheless diagnosed with ASA. He was treated with an ointment containing a corticosteroid and moisturizer, and his symptoms started improving within a month.

Accidental caffeine overdose after measuring error

An error while measuring caffeine powder had fatal consequences for a man in the U.K. The 29-year-old personal trainer ordered a small bag of caffeine powder to add to his drinks. Although he meant to add up to 300 milligrams (0.01 ounce) of the powder, the scale he used had a starting weight of 2 grams (0.07 oz). Immediately after consuming his drink, he felt his heart beating fast, and he started foaming at the mouth. His wife called an ambulance, but the man died later that day.

At the time, the coroner found a caffeine level of 392 milligrams per liter in the victim's blood — the equivalent of about 100 to 200 cups of coffee. The coroner said it appeared that the man was aiming for the middle of the range of the recommended caffeine dose but got his calculations wrong.

Folded stomach

Doctors managed to save a girl's life after she developed a rare and potentially life-threatening condition called gastric volvulus, in which part or all of the stomach rotates by more than 180 degrees. When this happened to the 12-year-old girl, she was left in crippling pain, could not breathe properly and couldn't pass stools.

Gastric volvulus can lead to an obstructed stomach, blocking the movement of food, blood and oxygen. According to the report of her case, the girl survived, thanks to the prompt diagnosis and surgical treatment. However, the condition is fatal in about 30% to 50% of cases.

Gastric volvulus is usually caused by a hernia, in which part of the stomach pushes into the chest cavity through an opening in the diaphragm. However, in the girl's case, the stomach folded over itself because the ligaments anchoring her stomach in place were loose.

Tumor in "extra" breast

A 63-year-old woman felt painful swelling in her armpit and sought medical help. Doctors saw that she had a mass of tissue, which an ultrasound revealed was an "extra breast." However, doctors also found a spherical tumor growing in one of the milk ducts in the extra breast. The tumor was benign and was successfully removed, according to the patient's case report.

This kind of tumor affects up to 3% of people in their normal breast tissue, but it is not commonly found in extra breast tissue. Polymastia, which refers to having extra breast tissue, is a relatively common condition, affecting up to 6% of females and 3% of males.

Diver's leaky blood vessels

Scuba divers plan their rate of ascent to avoid decompression sickness (DCS), which can be life threatening. DCS happens when dissolved gases in a person's blood form bubbles in a person's bloodstream and tissues. A diver's rapid ascent from a high-pressure environment in the deep sea to the lower pressure at the surface could trigger DCS. Symptoms include joint pain, nausea and headaches.

One diver had an extremely rare complication of DCS in which fluid started flowing out of his cells, doctors explained in the journal BMJ Case Reports. The man, who was in his 40s, went to the ER with shortness of breath after a 100-foot (30 meters) dive. While doctors might have suspected DCS, an expert on systemic capillary leak syndrome (SCLS) identified the diver's symptoms and helped provide the appropriate treatment for the complication.

It was suspected that air bubbles formed in the patient's blood vessels, triggering a "pro-inflammatory cascade which made the vessels more permeable, resulting in the leakage of protein and fluid," the expert said at the time. SCLS can be fatal, but in this case prompt diagnosis and treatment meant the diver was discharged in less than a week.

Locked-in syndrome

A case report describes the case of a 54-year-old man with locked-in syndrome (LIS), a rare neurologic disorder in which patients can't move or speak but can otherwise think normally. It has been described as "being a prisoner in [your] own body." 

Historically, people with LIS have interacted with others by moving their eyes or blinking; nowadays, though, there are various assistive devices available and in development to help people communicate. The main cause of LIS is damage to a part of the brain called the ventral pons; the damage most commonly results from a stroke but can also be caused by trauma; infection; masses, such as tumors; or demyelinating disorders, such as multiple sclerosis. 

Patients can live for years with LIS. However, this patient had recurrent infections and died from pneumonia 36 days after being diagnosed with the condition.

British psychologist Kimberley Wilson has worked with people from all backgrounds following her years working as a therapist at London's Holloway Prison, which was Europe's largest women's prison at the time. But those formative years shaped the advice Wilson gives her clients and patients to this day.

During her time at Holloway, Wilson learned about surprising links between diet, mental health and behavior in the population she worked with. Those early findings were so promising they inspired the work Wilson has done over the past decade, as well as her two books: "How to Build a Healthy Brain" (Yellow Kite, 2020) and "Unprocessed: How the Food We Eat is Fueling our Mental Health Crisis" (Ebury Publishing, 2023).

In an interview with Live Science, Wilson described her journey from those early years to her current practice, emphasizing the links between mental health and nutrition.

Sascha Pare: You became interested in nutrition after training as a psychologist — how did food first pop up on your radar?

Related: How long does it take to digest food?

Kimberley Wilson: My first proper job when I qualified was in a prison working for a charity developing and offering therapy to prisoners. The thing about women at that time [between 2008 and 2013] — and I'm going to assume it's still the same — is that, although they only made up about 6% of the overall U.K. prison population, they accounted at the time for about 50% of the self-harm that was occurring across the entire U.K. prison estate. [Recent figures show that in 2022, women prisoners accounted for 29% of self-harm incidents while making up only 4% of the U.K. prison population. And between 2022 and 2023, rates of self-harm increased by 43% in female establishments.] 

It was around that time that this replication [in the Netherlands] of a [2002 U.K.] study came out. They had taken a cohort of violent male prisoners and improved their nutritional status through supplementation [capsules containing vitamins, minerals and fatty acids]. They found that objective incidence of violence — and I say objective, so not like "How are you feeling? Do you want to punch anyone today?" but actually going through the log book at the end of the wing and counting how many infractions had happened — were 30% lower in the supplemented group compared to the placebo group.

That was just extraordinary to me. I was already working in prison, I was already thinking about safety and harm — and here was this good quality, gold standard research demonstrating that a safe, accessible, low-risk, low-cost intervention could meaningfully improve not just the wellbeing of the prisoners, but also the staff.

SP: That sounds very promising. How did this new information sit with how you were trained as a psychologist?

KW: This raised really interesting questions as a psychologist as to actually how much of my patients' behavior is within their grasp and how much is it being influenced by things that they are completely unaware of. I just found it a fascinating area and also one that was really relevant to the work I was trying to do.

SP: And how was the new information received by your peers and colleagues? Did you implement any nutritional changes during your time working at the prison?

Related: Why do we crave comfort food? 

KW: I tried to speak to the governor [warden] and head of health care to tell them about this and to see if we could do a small trial, or if we could take our riskiest women and offer them a supplement. But I got no response whatsoever: it was just crickets. It's really interesting how unwilling people are to engage with that question. Since then, we have had two more replications of that data, so we've got four now — in the U.S., U.K., the Netherlands and Singapore — showing the same thing: When you improve nutrition, you reduce violence.

SP: So, you were convinced by the data that was coming out, even if some of your colleagues weren't. Fast forward a few years: You left your forensic work at the prison and opened a private practice in central London. How did you begin to integrate nutrition into your therapy work?

KW: I did my master's in nutrition and looked specifically at the role of nutrition in brain health, so I was looking specifically at brain health and neurodegeneration, and then within that I was thinking about how — broadly — a healthy brain improves mental health outcomes. That's when I started to think about nutrition with my clients and patients. 

SP: Do you think that interest in the kind of work you do — more holistic therapy that integrates lifestyle factors — has increased in recent years?

KW: There's certainly been more conversations about it, and that's also come with more skepticism, which I think is important, but I think there is a much broader appreciation certainly on social media. Could the brain be associated with the body in some way, and could the quality and status of your nutrition be playing a role in your neurological or psychological symptoms? I think those are really important questions — that reintegration of the brain into the body is absolutely crucial, I think, for the future of mental health treatment and research.

SP: The gut-brain axis immediately comes to mind here, but is there any more recent research demonstrating links between nutrition and brain health?

KW: When we look at maternal diet and brain health outcomes in offspring, yes, there's a very clear association. For example, we know without any hesitation that iodine insufficiency is the leading cause of preventable brain damage in the world and leads to permanently suppressed IQ. Similarly, we know that the higher the maternal intake of omega-3, the larger the baby's overall brain volume and connectivity. [These studies are small, observational and were not designed to show that higher omega-3 intake caused higher brain volume.]

In terms of broader dietary intakes, that data is kind of coming in now. First of all, a diet that's high in ultra-processed foods (UPFs) is lower in nutrients. We see that across the world, and the issue for the brain with that relationship is that the brain is the hungriest organ in the body. It has a huge nutrient demand and so the concern is, if we have a population of both adults and children that have a high proportional intake of UPF, are their brains getting what they need to function well? The likelihood is no. 

People who have higher UPF [intake] have increased incidence of depression and anxiety, and increased risk of depression and common mental health conditions later on. They also have faster cognitive decline and greater overall dementia risk. 

[High UPF intake is tied to other major factors that impact people's health — for example, people with low incomes who face food insecurity and receive government food benefits often consume more processed foods, and they are thus facing additional stressors beyond the foods they eat.]  

SP: How do you pass that information on to your clients and patients?

KW: I just try to present the evidence: "The evidence suggests to us that just getting a few more fruits and vegetables into your diet will help you feel a little bit better. Is this something you'd be willing to try?" [Studies showing the impacts of fruit and vegetable intake on mood are largely observational.] 

For some people nutrition might be a significant influence on how they're feeling, but for other people it's really not, and so you can just give it a bash for a while and see.

SP: You also do a lot of science communication work on your social media platforms. Do you communicate differently online, maybe in a way that's more prescriptive? (I must confess I've had a stalk of your Instagram.)

KW: The ironic thing about social media is that people are looking for you to tell them what to do, whereas I'm just kind of like: "Here's some information, do with it what you like." I think it's important for people to have that information, but it's not a command.

Kimberley Wilson will be co-hosting a talk called "Gut Feelings" at this year's Cheltenham Science Festival, which will run from June 4 to 9. 

This interview has been edited and condensed for clarity. 

Many elementary-age children think artificial intelligence (AI) assistants like Alexa and Siri may have feelings or the ability to make decisions independently, a study suggests.

The research, published in the journal Computers and Education: Artificial Intelligence, investigated how 6- to 11-year-old children perceive household AI assistants, such as Alexa, Siri and Google Assistant. The study, conducted in Scotland through questionnaires and interviews, hints that children may overestimate and misunderstand the intelligence of these popular technologies.

"Children should be taught AI literacy in schools, and technology designers should take care that their AI products don't mislead children into thinking they are human-like," study co-author Judy Robertson, chair in digital learning at the University of Edinburgh, said in a statement. "AI is often designed to appear more human and intelligent than it really is, which is very confusing for children."

Of the 166 children surveyed for the study, 93% had a smart speaker at home. They reported using the devices to listen to music, ask questions, search for information, get help with homework, and listen to jokes and stories. Research by Statista, a data-analysis firm, estimates that 57% of U.S. households will own at least one smart home device by 2025, suggesting around 40 million children could have one in their house in the next year.

Related: Scientists create AI models that can talk to each other and pass on skills with limited human input

Despite their familiarity with these devices — or perhaps because of it — many of the surveyed children reported being uncertain about whether the gadgets possess human-like qualities, such as emotions or decision-making abilities. Just under one-third believed smart speakers could think for themselves, to some extent, while 40% thought they "maybe" could.

Notably, only 1% of the children actually categorized the devices as "human." Around 80% classified them as "AI," and 15% said they were "objects." But given that roughly two-thirds believed the systems might be able to think as we do, the researchers said the study highlights the risk of children overestimating the reliability and capabilities of AI systems.

Many children interviewed said that, if their Alexa breaks, it wouldn't be right to throw the device away, although this view was more common among younger participants. About 68% of the 8-year-olds in the study held this view, compared to 37% of 11-year-olds. But when asked if Alexa would feel left out if not included in a conversation, older children were more likely to say yes — 73% of 11-year-olds and 72% of 10-year-olds felt this way, while only 38% of 8-year-olds did.

"The findings reveal the importance of enhancing children's awareness and understanding of AI-supported technology to ensure safe and responsible interactions with smart technologies," study co-author Valentina Andries, who conducted the study at the University of Edinburgh but recently moved to the University of Oxford, said in the statement.

"This is becoming increasingly important in the current context of generative AI technology for various purposes, including in education," Andries added. Generative AI refers to deep-learning algorithms that generate new content, as ChatGPT generates text, for example.

Due to the rapid development and increasing availability of AI-related tech, everyone — not just young children — should try to recognize the limitations and capabilities of contraptions like smart devices, Madeline Reinecke, a postdoctoral researcher in the psychiatry department at the University of Oxford, and who was not involved in the study, told Live Science.

"I think it's important for all users, whether they're aged 5 or 50, to have an accurate picture of what these technologies are, and how they can best use them safely and responsibly," particularly as they're becoming more human-like, she said.

Reinecke suggests that additional studies into how both adults and children use and respond to such technology are needed. "There hasn't been much time for researchers to track what downstream impact they [emerging technologies] might have on children's cognitive and social development," she said.

However, regarding the University of Edinburgh's study, Reinecke noted that the children's overestimations of smart technology are likely "relatively harmless in the grand scheme" of their cognitive development.

On one hand, "smart speakers … offer an opportunity for children to learn more about the world around them," she said. "But it's imperative that they learn to think critically about where that information comes from."

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A lawsuit filed on Valentine's Day claims that several popular dating apps are "psychologically manipulative" and "addictive," encouraging "compulsive" use by people on the platforms.

The claim is aimed at Match Group, which owns a variety of online dating platforms including Tinder, Hinge, The League, Match and Plenty Of Fish. Depending on the outcome, the lawsuit could have wide-reaching implications, as an estimated 3 in 10 U.S. adults report having used a dating app at some point, according to the Pew Research Center.

But can a dating app really be addictive?

Related: Is there actually science behind 'dopamine fasting'?

Addiction to a behavior, rather than a substance

Among psychologists, terms like "addictive" can be controversial when applied to non-substances, such as video games or social media. Gambling disorder is the only non-substance addiction currently recognized by the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the gold-standard reference for psychological and psychiatric diagnosis used in the U.S.

However, the 11th Revision of the International Classification of Diseases (ICD-11), the manual of mental-health diagnoses released by the World Health Organization, also includes "gaming disorder," a condition in which people cannot stop using online or video games regardless of how much playing disrupts their daily lives.

Ultimately, what's going on in the brain when someone feels compelled to keep swiping on Tinder or scrolling on TikTok does look similar to what's happening when someone experiences physical addiction to a substance, said Larry Rosen, a professor emeritus of psychology at California State University, Dominguez Hills and co-author of "The Distracted Mind: Ancient Brains in a High-Tech World" (MIT Press, 2016).

This is because connecting with a new match on Tinder or seeing a new notification pop up on a social site provides a burst of dopamine in the brain, Rosen told Live Science. "What's interesting is that a little bit of dopamine makes you feel good for a while," he said, "and then you habituate to it, and now you need more dopamine to feel just as good."

The urge to chase this dopamine high via dating apps is not perfectly analogous to becoming physically dependent on a drug. Because of that, stopping using dating apps is not as physically devastating as going through withdrawal from an alcohol addiction or heroin habit, for example. But in some ways, the underlying biochemistry is similar, Rosen said.

"Addiction is real and it's biological; it's our human need to feel good," he said. "So yes, this is a form of addiction," Rosen argued.

Related: Why do we get addicted to things?

Disagreement about the term "addiction"

Not everyone approves of using addiction language to describe people's use of dating apps, however. Kathryn Coduto, a professor of media science at Boston University who has studied dating apps since they first appeared on the market, said she sees addiction as a "really strong" term.

"I hesitate to act like users don't have a sense of control or determination over the technology, at the end of the day," she told Live Science. "That's not to say users are totally in control when they're using technology, or that there isn't a way to hold tech companies accountable."

The new class-action lawsuit, filed in federal court in California on Feb. 14, argues that dating apps promise to get their users off the sites as quickly as possible by efficiently pairing them with compatible people. Hinge's tagline, for example, is "The dating app designed to be deleted." But the app designers, the lawsuit argues, then employ "psychologically manipulative features to ensure they [users] remain on the app perpetually as paying subscribers."

These features, the lawsuit posits, are contrary to the apps' stated goal to get users real-life dates so they don't have to use the service anymore. Some of the game-like features on Tinder include the app's "deck of cards" style interface, in which users swipe left or right to reject or like potential dates rapidly, as well as pay-to-play features like "Super Boosts," which drive more views to a user's profile during peak usage times. The lawsuit specifically objects to Hinge's tagline, given the strategies it and other apps use to keep users engaged.

In a statement to Reuters, Match Group called these claims "ridiculous."

Related: Loneliness is bad for your health, study suggests

The drive to engage users and keep them on a platform goes well beyond dating apps, Rosen said. "Every single company has at least one, if not more, people on staff who have a PhD in psychology or social science," he said. "They are tasked with one job, which is to get eyeballs there and keep them there."

Dating apps are particularly motivated to keep users swiping, Coduto agreed. Without users, there is no dating pool. Without a dating pool, there is no dating app, she said.

The strategies companies use to do this are largely based on positive reinforcement, Rosen said. Positive reinforcement provides a reward for a desirable behavior — in this case, staying engaged with the app — so that the recipient is encouraged to do it more in the future. (That's opposed to negative reinforcement, which rewards a behavior by removing an undesirable stimulus when people do it.)

"Sometimes the best positive reinforcements are nothing tangible," Rosen said. "They're applause; they're congratulations; they're your name on the leaderboard. The better you feel, the more likely you are to go and play."

These apps also plug into the anxiety of an unchecked notification, Rosen added. Imagine getting a text message but not being able to immediately pick up your phone and see what it says. Feel stressed? That reflects rising levels of the stress hormone cortisol in your system. Check the message and satisfy your curiosity, and those cortisol levels will drop.

Compulsive use of apps

Many people do struggle with compulsive use of all kinds of apps, said Dr. Brett Kennedy, a psychologist and the co-director of the Digital Media Treatment & Education Center in Boulder, Colorado.

In psychology, a "compulsion" refers to a behavior that a person feels a strong urge to do, often repeatedly, to reduce feelings of anxiety or stress. Research has shown that taking away someone's mobile device can be an anxiety-inducing event; in one 2014 study, researchers forced college students to sit quietly without their phones for 75 minutes. They found that all but the lightest users became more anxious the longer they were without their phones.

"We really have this anxiety or FOMO, the fear of missing out," Kennedy said. The constant accessibility of technology, he said, "sets the stage for people to lose perspective on what that actual balance is. And some people are better than others at it."

Related: What does love do to your brain?

In a 2020 study, Coduto found that people who scored higher on a standard scale of social anxiety were more likely to report that they could not control their use of dating apps, especially if they also reported experiencing loneliness.

"For someone who is socially anxious, being on a dating app probably feels a little bit safer [than making a pass at someone in person]," she said. The tradeoff, she said, is that "that safely feels almost like endless potential." Your next match could be just a few swipes away, the apps claim.

There is a positive side to the gamification of apps, Coduto said — these strategies do make using the apps fun and rewarding, and for some people, that level of whimsy might be just what they're looking for in their dating life. For people who are struggling to rein in their use of the apps, though, strategies to limit their time with tech are often helpful, Kennedy said.

"I often have to work with people to structure their time and to be purposeful with their time and the use," he said. "And to educate them on this reality — that it is not designed for you to be purposeful and mindful."

Just because psychological scientists have found evidence of addictive or compulsive use of dating apps doesn't mean the lawsuit will succeed; the ultimate outcome of the lawsuit will also involve interpreting consumer-protection law. But the results could be interesting for the future of dating apps, Coduto said.

"I'm very curious to see how legal definitions of things like 'addictive' and 'compulsive' come into play," she said.

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People with depression may struggle to recall specific memories about their lives — for instance, a dinner party with friends or a visit to their favorite coffee shop. Now, a small trial suggests that "scent therapy" could help people with depression unlock those difficult-to-access autobiographical memories (AMs).

The trial, described Tuesday (Feb. 13) in the journal JAMA Network Open, included 32 adults with major depressive disorder and used familiar scents — such as coffee grounds, oranges and Vicks VapoRub — as prompts for the participants to recall specific memories. So, for example, if presented with coffee, a person might think of meeting up with their sibling for lattes on a specific spring afternoon, as opposed to just generally thinking of the local cafe they often visit.

Previous studies had tried similar memory tests but instead used words and pictures as cues for the participants. So, in the new trial, the scientists switched between scents and words as cues, to see if one type of trigger might be more effective at jogging people's autobiographical memories. They found that the participants recalled more specific memories when cued by smell.

Related: How does the brain store memories?

"It was surprising to me that nobody thought to look at memory recall in depressed individuals using scent cues before," senior study author Kymberly Young, an associate professor of psychiatry at the University of Pittsburgh, said in a statement. Scents are known to trigger strong, often emotional, memories in a unique way that other stimuli don't necessarily do.

"The olfactory system is the only sensory system that has a direct, superhighway access to the memory centers of the brain and the emotional centers of the brain," Michael Leon, a professor emeritus of neurobiology and behavior at the University of California, Irvine, who wasn’t involved with the new study, told NBC News. "All the other senses have to take the side streets to get there."

So, in theory, harnessing smell might be a good strategy for rewiring those emotional centers in depression and unlocking the memories they help to recall. "If we improve memory, we can improve problem solving, emotion regulation and other functional problems that depressed individuals often experience," Young said.

That's because, when it comes to memories, people with depression have a bias toward lumping individual events into broad categories and overgeneralizing the emotions tied to those events. For instance, a person might recall "time spent in college" as one category and paint that whole chapter of life as negative, without being able to pluck out individual, positive memories from that time.

This memory bias keeps the person entrenched in negative thinking patterns that are difficult to break. For instance, it can make it more difficult for a person to debunk negative, overgeneralized thoughts about themselves, such as "I am a failure."

The trial sought to disrupt those patterns by helping people recall specific memories. Study participants were asked to recall memories — positive or negative — after sniffing 24 odor samples from glass jars or after hearing words that described those odors. The odors covered a broad range, including lavender, cumin, whiskey, cough syrup and shoe polish.

"In the verbal cue condition, 52% of memories were specific, while in the odor cue condition, 68% of memories were specific," the study authors wrote in the paper. "Additionally, we found that these AMs are rated more arousing and vivid upon recall," compared with the memories cued by words, they noted.

The team plans to run future trials with the addition of brain scans, to see how the amygdala, a key emotion-processing hub in the brain, responds to the treatment.  

"We hope this initial study spurs larger studies in more diverse samples that include healthy control participants" — meaning people without depression — "to further investigate and explain these associations," they concluded.

This article is for informational purposes only and is not meant to offer medical advice.

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The now-famous "love languages" were first introduced in a book penned by Gary Chapman, a Baptist pastor and self-named marriage counselor. His book "The 5 Love Languages" (Northfield Publishing, 1992) skyrocketed in popularity, with its various editions selling around 20 million copies and landing a New York Times bestseller title.

Nowadays, Chapman's theory is all over TikTok, where content creators talk about their own love languages and question their compatibility with their partners. But experts have long challenged the notion because there's a lack of consistent evidence that the love languages improve communication between partners, and they may not fully reflect the ways people receive and express love.

Now, in a paper published in January in the journal Current Directions in Psychological Science, researchers outline the weaknesses of the love language theory and offer a science-backed alternative.

Related: What does love do to your brain?

"Our critique does not label the love language system as outdated, per se, but rather highlights its lack of scientific foundation," said study co-author Gideon Park, a doctoral student in psychology at the University of Toronto. "Based on the review, our paper ultimately suggests that you cannot put people into arbitrary boxes," Park told Live Science.

Paul Eastwick, a psychology professor at University of California, Davis, says that the study has sound arguments.

"I think Impett [the senior author] and colleagues are absolutely correct in their analysis," Eastwick told Live Science in an email. "I usually tell people that the love languages are fine, and using them with your partner will generally make your partner feel appreciated and loved. But there's no evidence for 'matching' whatsoever, and there is no shortcut to meaningful and effective communication."

To see whether love languages were scientifically sound, the researchers evaluated existing research and questioned three major assumptions Chapman offers in the latest edition of his book: that each person has a primary love language, that there are five distinct languages and that "speaking" the same language leads to a higher-quality relationship.

Does everyone have a primary love language?

The five love languages are words of affirmation, quality time, receiving gifts, acts of service and physical touch, and Chapman argues that each person "speaks" in one primary language. This reflects the main way they express love and most desire to be loved.

But as it turns out, people like to be loved in all of the languages, and there isn't one preference. In studies that conducted surveys with couples, results have shown that people tend to endorse all five as meaningful ways of expressing love, and they vary in context. For example, spending quality time might be a way to express love in everyday life, but receiving a gift might be preferred on a special occasion, like Valentine's Day or an anniversary.

Forcing people to pit the five love languages against one another is counterintuitive, Park said.

"When researchers have asked people to independently rate the value of each expression, they tend to rate them all highly," Park said. "So, in real life, when people do not actually need to make these trade-offs, they see all five ways of expressing and receiving love as important."

Are there five love languages?

Chapman puts each of the love languages forward as distinct and separate constructs, but studies and surveys suggest that the ways people express and receive love are more integrated and complicated than that.

There is research suggesting that these five modes of expressing love do, in fact, exist. However, the review argues that Chapman's description limits expression to those five languages, unintentionally undervaluing other efforts, like making new friendships for their partner. Plus, research found that granting autonomy and offering space to foster individual needs outside of the relationship are other important needs in healthy relationships.

"The five things that Chapman picks, they all make sense," said Gary Lewandowski, professor and former chair of the Department of Psychology at Monmouth University, who was not involved in the study. "But I think there are things that make even more sense — like where each partner works to facilitate personal growth and each other."

Related: Brain signature of desire uncovered in lovesick rodents, and it may be in people, too

Does speaking each other's love language lead to stronger connections?

Researchers have tested this assumption by investigating whether partners who have the same primary love language are more satisfied in their relationships. Yet no study has found strong evidence to support the claim. These studies surveyed couples on their satisfaction levels with their partners as well as their love language preference, and it didn't seem to play a significant role.

Researchers have also examined whether people report greater relationship satisfaction when their partner expressed love to them in their preferred love language. The study evaluated this by surveying more than 980 individuals in couples on whether or not they felt happier when their partner expressed love using their preferred language. It seemed successful.

But although this idea garnered some support, the review argues that the same kind of satisfaction could occur if the partner used any love language, not just the preferred one. In fact, research recently presented at a 2023 conference found that "expressions of all love languages were positively associated with relationship satisfaction regardless of a person's preference, with very little evidence of matching effects," the review noted.

An alternative to love languages

Despite the weaknesses of Chapman's theory, Park said the book has an upside: It raises awareness around unmet relationship needs. However, the book's core assumptions should be "approached with caution," he said.

For that reason, Park and colleagues propose a more realistic framework for relationships: seeing love as a nutritionally balanced diet. The metaphor suggests people need multiple essential nutrients to maintain satisfying relationships — while you could survive for some time on carbs alone, you also need protein, fat and vitamins to thrive. So rather than fixating on one "love language," people can express and receive love in a variety of ways that meet their and their partner's evolving needs.

"People often value putting themselves and others into arbitrary boxes, as it allows them to rely on heuristics and archetypes, making it easier to understand themselves and the world," Park said. "But we need to learn how to do all those things and realize that people and relationships are not stable entities but are, instead, growing and changing over time as people and couples encounter new life circumstances."

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website! 

The brain activity of people who are easily offended is different from that of people who aren't as prone to getting riled up, a new study suggests.

Many people would consider a missed text from a best friend to be a harmless, accidental act. Maybe they're busy, or perhaps they read it and simply forgot to reply. However, some people are more likely to misconstrue this action as aggressive or hostile, thinking they're perhaps ignoring you on purpose. Scientists call this tendency to assume the worst in people "hostile attribution bias," and it can make people more likely to be aggressive, experience poor mental health and struggle to maintain healthy relationships. 

A new study suggests that people with hostile attribution bias display a unique signature of brain activity in part of the brain called the ventromedial prefrontal cortex (vmPFC) when another person's actions result in a negative outcome for them. Among other functions, the vmPFC is involved in emotional regulation, decision-making and self-perception. 

"The VmPFC is a high-order brain region that integrates sensory information about the external world with internal states and beliefs," Yuan Chang Leong, co-senior study author and an associate professor of psychology at the University of Chicago, told Live Science in an email. In other words, the vmPFC helps control how we react to social situations based on our already established biases.

Related: Neuralink chip implanted into human brain for the 1st time, Elon Musk says

The results of the new study, published Monday (Feb. 5) in The Journal of Neuroscience, suggest that the vmPFC plays a role in governing a person's interpretation of a social situation by integrating information about the unfolding scenario with their preconceived notions and memories, Leong said.  

Understanding the brain mechanisms behind hostile attribution bias could bring scientists a step closer to developing ways of mitigating it — for example, through more targeted interventions to reduce aggressive behavior and promote healthier relationships, the authors wrote in the paper. 

In the study, 58 volunteers listened to audio recordings of people describing 21 hypothetical social scenarios. On average, the mini-podcasts were around 40 seconds long and involved a character executing actions toward the listener — the study participant — that could have a negative effect on them. For instance, in one scenario, a professor forgot to write a letter of recommendation for the participant after they'd agreed to do so. 

After listening, the participants rated whether they thought these actions were intentional and hostile — for example, the professor was purposefully retaliating against them — or unintentional, meaning they simply forgot to write the letter. 

Throughout the experiment, each participant wore a fitted cap on their head that measured their brain activity using a technique called functional near-infrared spectroscopy (fNIRS). The researchers found that, during the recordings, fluctuations in brain cell activity in the vmPFC was similar among individuals with similar levels of hostile attribution bias and differed in those without the tendency. 

This suggests that this bias has steadily shaped how their brains respond to such scenarios, driving the activity to look the same, Leong said. Using the brain-activity readouts, the authors could predict with 75% accuracy whether someone had low or high hostile attribution bias, based on the pattern of activity in their vmPFC.

The authors also found that participants who exhibited less hostile attribution bias scored higher on a survey that assessed another psychological concept, called attribution complexity. This measures how likely someone is to consider that there may be many complex explanations for certain behaviors. 

As such, "fostering attributional complexity could be a potential strategy to mitigate hostile attribution bias and ultimately promote healthier social interactions," the authors wrote in the paper.

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

The word resilience can be perplexing. Does it mean remaining calm when faced with stress? Bouncing back quickly? Growing from adversity? Is resilience an attitude, a character trait or a skill set? And can misperceptions about resilience hurt people, rather than help?

To sum it up in a sentence: Resilience is the ability to manage stress in effective ways. It's not a static quality or attribute you're born with, or a choice of attitude. Instead, it's a set of skills that can be developed by repeating specific behaviors. As a clinical psychologist, researcher and educator specializing in training people to cope with stress more effectively, I know that resilience can be developed.

But as with physical fitness, you can't get stronger abs by just wanting them. Instead, you have to repeat specific exercises that make your abs stronger; intention alone just won't do it.

Cultivating resilience is much the same. Like physical fitness, resilience is not a single quality but rather many ingredients that contribute differently to a range of strengths and situations. For instance, one may handle relationship issues rather well but be unable to cope with the stress of a traffic jam.

Related: COVID pandemic had 'minimal' effect on mental health, study says. Is that true?

Some building blocks of resilience are factors that are largely beyond one's control, such as greater income and education and having supportive environments. Some are things you can do in your daily life, such as exercise, hobbies and activities, and getting adequate sleep. Other facets might take more time to develop, such as nourishing supportive relationships, building skills for tolerating distress and regulating emotions, meditation, incorporating spirituality or religion and practicing less self-criticism and more self-compassion.

Resilience can be cultivated

Confusing connotations about resilience pervade not only the scientific literature and mental health approaches but also popular culture. The idea that difficult experiences make someone resilient is incorrect, or at least incomplete.

During the first year of the COVID-19 pandemic, I heard people claim that "children are resilient." However, one of the largest research investigations about difficult childhood experiences, the Adverse Childhood Experiences study, conducted in the 1990s at Kaiser Permanente with over 17,000 adults, established that cumulative stressors experienced in childhood impair both mental and physical health. It also found that more stress predicts worse outcomes.

What actually helped people be more resilient during the COVID-19 pandemic?

Studies show that the same building blocks mentioned above helped people navigate the pandemic with greater well-being. Many of these same building blocks also improve people's outcomes following other stressful experiences, such as unemployment, cancer, divorce and exposure to violence.

All of this says that resilience can flourish by incorporating specific behaviors and creating healthy environments. People often assume it's optimal to remain relatively unaffected by stress — that is, to "get over it" quickly. In many cases, that might be the case. If you forget an important meeting, for example, a response of "Oh no! I need to apologize right away and reschedule" is probably healthier than punching a wall or concluding that you're a terrible person.

But what if a relationship ends? Is it always best to get over it quickly, or could a longer reflection and healing process lead to deeper learning and growth? What looks like resilience could instead be suppressing, numbing or hiding feelings. Those tendencies are linked with worse mental health.

This is why the concept of resilience is somewhat nuanced; some people who seem resilient are just covering up, or coping in an unhealthy way — such as using alcohol to cope with difficult feelings.

Sometimes painful feelings or experiences contribute to personal development. Post-traumatic growth refers to the positive changes that some people report after trauma, especially when they incorporate some of the resilience "building blocks" listed above. This includes better relationships, a greater appreciation of life and enhanced spiritual or philosophical understanding. Rather than expecting yourself to always feel good or to bounce back quickly, in some situations it may be wise to allow yourself to experience deeply challenging feelings and the personal growth that can ensue.

Related: Earwax may reveal how stressed you are

Resilience isn't always the answer

Resilience is more complex than being mentally tough or not letting things get to you. Pressuring yourself to appear okay when you're not — also known as emotional perfection — could make things worse and prevent you from seeking support. Sometimes, changing stressful environments, such as a job or living situation, rather than just adapting to them is a healthier choice.

This is why resilience can be a loaded term. Although coping with challenges has its place, for trauma survivors, people who have experienced racism or homophobia, or those living in regions especially affected by climate change, and many others, resilience falls flat. The word comes across as tacitly accepting the status quo rather than demanding accountability from those who caused harm or working to reduce the sources of stress.

Overemphasizing resilience can reinforce racial injustice by suggesting that people who are subjected to it are resilient enough to handle it. Having to wear a mask of resilience or put on a smile can add to the burden of racism, making resilience exhausting. Having to continually adapt to microagressions and other forms of racism takes a mental and physical toll, such that resilience to racism comes at a cost.

A one-sized-fits-all approach to resilience doesn't work for every person and problem. But most of us can benefit from nourishing some of the building blocks of resilience, such as cultivating supportive relationships, physical exercise and self-compassion.

Becoming more resilient is a process. We can benefit from working on the building blocks of our own individual resilience, and from initiatives in schools, workplaces and other environments that promote resilience more broadly.

The number of factors affecting resilience may seem daunting. The upside is that you can choose from many effective ways of building resilience to determine the most suitable approach for you.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

A new app that delivers a specialized form of talk therapy to users might help people cope with tinnitus, a small study shows.

Tinnitus, or persistent ringing in the ears, does not have a single cause, but it is often related to hearing loss; a recent study suggests the condition may stem from hard-to-detect nerve damage. Tinnitus can sometimes go away on its own over time, but in other cases, it worsens, with chronic cases lasting three months or longer. Various treatments can help people manage the condition, including cognitive behavioral therapy (CBT), a specialized form of talk therapy that focuses on identifying and changing distorted thought patterns and their associated behaviors. 

In the new study, published Jan. 9 in the journal Frontiers in Audiology and Otology, researchers tested whether 28 people with tinnitus would respond to a form of CBT delivered via a chatbot-based app called MindEar. In some cases, the chatbot therapy was also paired with virtual sessions with a trained psychologist. With or without the psychologist, the participants saw noticeable improvement after using the app.

Previous research has "laid the groundwork to say yes, CBT is very good," Fatima Husain, a professor of speech and hearing science at the University of Illinois Urbana-Champaign who was not involved in the study, told Live Science. Now, this study is "leveraging technology to make it even more readily available and cost effective," she said.

Related: 1 billion teens and young adults risk hearing loss from listening devices 

CBT does not change the sound of ringing that people with tinnitus experience, but it can help them adjust to and learn to live with the noise.

Not everyone with tinnitus is bothered by the ringing, but about 20% of those affected are distressed by the noise, Husain told Live Science. This leads to anxiety, depression and attention problems. In-person CBT can be expensive and difficult to access, but an app like MindEar could potentially reach more people, she said. 

In the new study, half of the participants received CBT treatment through the chatbot alone for eight weeks, while the other half also had online sessions with a clinical psychologist. 

The participants also took several tests before, immediately after, and then two months after the treatment to evaluate their levels of distress, depression and anxiety related to their tinnitus.

Both treatment groups had a notable reduction in distress related to tinnitus, according to the survey they used, known as the tinnitus functional index. Immediately after treatment, the chatbot-only group had a 46% reduction in this measure, while the hybrid group had a 64% reduction. At the two-month follow-up, both groups saw a 64% reduction. 

Although the participants indicated that the treatment didn't change their perception of the ringing, they reported that it helped them relax, maintain a sense of control, and sleep better.

Husain said she sees potential in apps like this to be even more accessible in their design. For instance, they could be translated into different languages, she suggested.

An obvious limitation of the study is its small size, Husain noted. She said she views the research as preliminary and a larger trial with hundreds of people should follow. 

In addition, the authors noted that the study didn't have a control group that didn't receive treatment, as a point of comparison. In addition, the participants had mostly mild symptoms of anxiety and depression, making it difficult to say if this treatment would work well for people with more severe levels of distress.

Future studies might include brain scans along with the surveys the researchers used, Husain said. As a researcher who uses neuroimaging in her work, Husain said it might provide insight into how tinnitus and its treatment affect the brain.

"What I would like to see is what happens in the brain as [the treatment is] happening," she said.

This article is for informational purposes only and is not meant to offer medical advice.

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website! 

After a viral infection robbed Chrissi Kelly, an American archeologist living in the U.K., of her sense of smell, she no longer felt like herself. It was as if she were "floating away," untethered from the rest of the world. Smell, she says, is something that binds us to nature and to our family, and without it, we cannot fully participate in everyday life. She missed the social part of scents: the deep joy of hugging a loved one and taking in their personal aroma. "I found living without the sense of smell profoundly disorienting," she says.

Kelly felt so strongly about what happened to her that she started a charity called AbScent to help people with smell loss. Kelly's perception that smell forms part of a person's identity is now receiving confirmation from recent research findings. A 2023 study from European researchers found, for instance, that not only can we pick up the scent of other people's fear or anxiety, but such emotions affect how we feel, too. Another study from China showed that people with better olfaction have more friends. "We see all kinds of behavioral effects," says Shani Agron, a neurobiologist at the Weizmann Institute of Science in Israel.

Humans have a long history of disregarding our noses — even Darwin claimed that the sense of smell is of "extremely slight service" to people. According to Bettina Pause, a biological psychologist at Heinrich Heine University Düsseldorf in Germany, one reason may be that social olfaction happens outside of our conscious attention. "The only thing I might know about this conversation is that my body feeling changes," she says. Yet humans seem quite able to pick out someone else's body odor. One study found that after shaking hands with people of the same gender, people reflexively sniffed their right hand more than twice as often as they did before the greeting.

Related: Why can't we smell ourselves as well as we smell others?

We pick up quite a lot of information from sniffing the body odor of people around us: we can recognize our kin, tell who is genetically related and pinpoint potential friends (we tend to choose friends who are genetically similar to us and have similar body odor). In one study, most new mothers were able to identify their baby by its smell after spending as little as 10 minutes together, and newborns can recognize their mother, too.

Adult human sniffers, meanwhile, can match pairs of identical twins by their body odor, even if the siblings live apart. In a 2022 study, researchers at the Weizmann Institute of Science managed to predict which volunteers would bond together simply by comparing their body odor — a task performed both by human smellers and an electronic nose (a device that looks like an old CB radio with a hose). The scientists discovered that people who smelled similar to each other were more likely to enjoy chatting and report that they felt instant chemistry. This goes along with earlier research showing that we subconsciously choose friends who share some of the same genes.

What's more, if we were to chat with someone feeling happy, chances are we would detect their current emotional state through smells that reach the nose. In one experiment conducted in the Netherlands, volunteers watched cheerful videos while holding absorbent pads in their armpits. Later, when another group sniffed the pads, measurements of their facial muscles' activity revealed that their mood improved, too: their smile muscles moved more.

Yet it's not only happy feelings that can be communicated through body odor. A 2020 study by Pause and colleagues showed that women's brains reacted more strongly when they smelled the sweat of men who had played an aggressively competitive game compared with the odors of men who had just enjoyed a calm construction game. It turns out that women also proved to be particularly sensitive to odors that signaled male anxiety. On picking up such odors, they became more risk-avoidant and less trusting. "Anxiety is a signal of, 'Please, I need help,'" Pause says. This, she believes, may explain why women appear more attuned to the smell of anxiety — historically, in distressing situations, it was women that cared for the young and the feeble. Such evolutionary links could also explain why women with more discerning noses perform better at tests of empathy, as revealed in a small 2022 study carried out by Pause and her colleagues.

In general, a sensitive nose seems to be an asset that enhances our deeply social life. Those who could better tell apart everyday odors also reported less loneliness, a 2020 study of 221 volunteers concluded. In other experiments, people with a better sense of smell had a larger social network and more friends, and they met with those friends more often. Functional magnetic resonance imaging of the brain, meanwhile, revealed that the same brain circuits may be involved in both our sense of smell and the size of our social circle.

For now, however, the mechanisms of how exactly humans pick up body odors and translate them into changes in our behaviors remain largely a mystery. "It's a multifaceted problem that we have yet to really begin to tease apart," says Johan Lundström, a neuroscientist at the Karolinska Institute in Sweden. Scientists are also just beginning to pinpoint which chemicals in body odor may be responsible for influencing social connections. One such molecule may be hexanal, which gives off a pleasant whiff of freshly cut grass — and appears to boost trust in people. Yet we still don't know if those who have more hexanal in their body odor are perceived as more trustworthy, says Monique Smeets, a social psychologist at Utrecht University in the Netherlands.

More research will likely follow because, as Agron says, "The pandemic really put a spotlight on the sense of smell." Even though omicron appears to be less damaging to our noses than previous COVID variants were, a 2023 study estimated that 11.7% of adults of European ancestry who have been infected with omicron have had some amount of olfactory dysfunction. People with smell loss may end up missing out on important but subconscious ways of communicating with others. And smell should be valued because olfaction is the most honest of our senses — something that, unlike our words or facial expressions, we just can't fake. "I can laugh even though I'm sad or aggressive, but I cannot intentionally change my chemical messages," Pause says. "It's kind of the only information which you can trust."

This article was first published at Scientific American. © ScientificAmerican.com. All rights reserved. Follow on TikTok and Instagram, X and Facebook.

The dawn of a new year marks a fresh start and motivates many people to break bad habits. Some are easier to shake than others, however, and the tendency to procrastinate is among the stickiest.

Whether it's finishing a piece of work, sending an email or going for a run, some tasks can feel insurmountable. The easiest way to avoid these tasks is to put them off until later or to never complete them at all. But why do people procrastinate, and is there anything we can do to reduce this tendency? 

"At its heart, procrastination is about avoidance," Fuschia Sirois, a professor of psychology at the University of Durham in the U.K., told Live Science. Rather than the task itself, however, it's often the emotions attached to an activity that cause people to recoil, she said. 

Tackling the first lines of a college essay may bring up feelings of self-doubt, for example. When you're faced with a broad question or topic to write about, the lack of clear instructions can trigger a fear of not getting it right or of what might happen if you get it wrong, Sirois said.

Related: Do New Year's resolutions really work?

Procrastination is a specific form of delay that is both unnecessary and voluntary, meaning it isn't caused by the person's need to prioritize other tasks or by an unforeseen emergency, Sirois said. The person procrastinating usually does so despite knowing that the task is important or valuable to them or others, and that putting it off could be detrimental to them or others, she added.

Chronic procrastinators typically struggle to manage and regulate their emotions, Sirois said. In a 2021 brain imaging study, Sirois and her colleagues found that college students with a higher volume of gray matter in the left dorsolateral prefrontal cortex — a region of the brain associated with self-control — were less prone to procrastination than their peers were. The more neural connections there were between this part of the brain and the frontal regions, the better the students were at regulating negative emotions, focusing on long-term benefits and sticking with tasks. Those with fewer connections between those areas were more likely to procrastinate at the cost of future rewards, the researchers concluded.

Difficulties in emotion regulation partly explain why people with attention-deficit/hyperactivity disorder (ADHD) are more likely to procrastinate.

A 2018 study also showed that the threat detection center of the brain, the amygdala, tends to be larger, and therefore more sensitive, in people who procrastinate. "The threat can be something tiny," Sirois said — how to word an email, for example. But the anticipated discomfort may be strong, so the urge to avoid discomfort may override any considerations of the consequences of not completing the task.

The fewer connections that existed between the amygdala and another region of the brain called the dorsal anterior cingulate cortex, which determines how we react to perceived threats, the more likely people were to put things off, according to the study.

"Like any personality trait, there are some biological underpinnings," Sirois said. Research suggests that procrastination is linked to impulsivity on a genetic level and may be a heritable trait. Sirois agreed that "there can be some genetic underpinnings, but that doesn't mean you're stuck and that's who you are."

Environmental factors are just as important in shaping our response to aversive tasks, Sirois said. Someone who doesn't usually procrastinate can do so if they find themselves in a situation that depletes their coping resources over a long period of time, such as the death of a family member.

"Procrastination becomes a quick, easy and 'dirty' way of coping with something, albeit in an avoidant way, when your coping resources are maxed out," Sirois said. But procrastination can pile on more stress by leaving a task hanging over a person's head, thus triggering a vicious cycle that can damage mental health, lower academic performance and lead to financial distress. 

Luckily for those of us who drag our feet — it took the author of this article eight months to start writing it — research has shown that learning to manage negative emotions can help reduce procrastination. Sirois recommended taking a step back when a task feels overwhelming to assess what emotions the situation has triggered and why you wish to avoid them. In the case of a college essay or work assignment, it may help to clarify any uncertainties about what the task actually is or to break it down into smaller tasks, Sirois said. Finding something meaningful about the task and rewarding yourself for finishing it might also be helpful, she added.

But if this is the year you want to stop procrastinating, let your resolution be to exercise self-compassion. "Forgiveness for your procrastination is very effective in reducing subsequent procrastination," Sirois said.

Time is one of those things that most of us take for granted. We spend our lives portioning it into work-time, family-time and me-time. Rarely do we sit and think about how and why we choreograph our lives through this strange medium. A lot of people only appreciate time when they have an experience that makes them realize how limited it is.

My own interest in time grew from one of those "time is running out" experiences. Eighteen years ago, while at university, I was driving down a country lane when another vehicle strayed onto my side of the road and collided with my car. I can still vividly remember the way in which time slowed down, grinding to a near halt, in the moments before my car impacted with the oncoming vehicle. Time literally seemed to stand still. The elasticity of time and its ability to wax and wane in different situations shone out like never before. From that moment I was hooked.

I have spent the last 15 years trying to answer questions such as: Why does time slow down in near death situations? Does time really pass more quickly as you get older? How do our brains process time?

My attempts to answer these questions often involve putting people into extreme situations to explore how their experience of time is affected. Some of the participants in my experiments have been given electric shocks to induce pain, others have traversed 100-meter-high crumbling bridges (albeit in virtual reality), some have even spent 12 months in isolation on Antarctica. At the heart of this work is an attempt to understand how our interaction with our environment shapes our experience of time.

Thinking time

This research has taught me that time's flexibility is an inherent part of the way in which we process it. We are not like clocks which record seconds and minutes with perfect accuracy. Instead, our brain appears to be wired to perceive time in a way which is responsive to the world around us.

The way in which our brain processes time is closely related to the way in which it processes emotion. This is because some of the brain areas involved in the regulation of emotional and physiological arousal are also involved in the processing of time. During heightened emotion, the activation caused by the brain attempts to maintain stability, which alters its ability to process time.

So, when we experience fear, joy, anxiety or sadness, emotional processing and time processing interact. This results in the sensation of time passing more speeding up or slowing down. Time really does fly when you’re having fun and drag when you're bored.

Changes in our experience of time are most profound during periods of extreme emotion. In near death experiences, like my car crash for example, time slows to the point of stopping. We don't know why our brains distort sensory information during trauma.

Ancient adaptations

One possibility is that time distortions are an evolutionary survival intervention. Our perception of time may be fundamental to our fight and flight response. This insight into time has taught me that in times of crisis, knee jerk responses are unlikely to be the best ones. Instead, it would seem that slowing down helps me succeed.

Being a time-nerd, I spend a lot of time thinking about time. Before COVID, I would have said that I thought about it more than most. However, this changed during the pandemic.

Think back to those early lockdown days. Time started to slip and slide like never before. Hours sometimes felt like weeks and days merged into one another. Newspaper headlines and social media were awash with the idea that COVID had mangled our sense of time. They were not wrong. COVID time-warps were observed around the world. One study found that 80% of participants felt like time slowed down during the second English lockdown.

We no longer had a choice about how and when we spent our time. Home-time, work-time and me-time were suddenly rolled into one. This loss of control over our schedules made us pay attention to time. People now appear less willing to "waste time" commuting and instead place a greater value on jobs with flexibility over where and when you work. Governments and employers still appear unsure how to grapple with the ever-changing time landscape. What does seem clear however is that COVID permanently altered our relationship with time.

Unfortunately, one downside to having greater awareness of time is greater realisation of just how finite it is. This year I turned 40, my eldest child started high-school and my youngest started primary school. What made these events so sobering for me was the fact that in my head, I am still only 23 years old. How can I already be halfway to 80? Is there anyway that I can slow time down?

Knowing that my actions and emotions can have a profound impact on my sense of time opens the tantalising possibility that one day I might be able to control my own experience of time. I often wonder if we may be able to harness the brain's ability to distort time and somehow re-purpose it so that we can control how we experience it. Then, trips to the dentist could feel like seconds not minutes and holidays would no longer be over in the blink of an eye.

Even though we may be a long way from controlling time, my research has taught me just how precious time is.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

In 1936, American writer Lowell Thomas wrote in his introduction to Dale Carnegie's book "How to Win Friends and Influence People" what would become an oft-repeated claim: "Professor William James of Harvard used to say that the average man develops only 10% of his latent mental ability."

This idea took on a life of its own, with some people later claiming that humans use only 10% of their brains. But is it true?

While it remains uncertain whether James, considered the father of American psychology, originated this statement, it is certain that it's indisputably false. Rather, "we're always using all of our brain," Erin Hecht, an assistant professor of evolutionary neuroscience at Harvard University, told Live Science.

"It's just such a funny myth," said Julie Fratantoni, a cognitive neuroscientist and head of operations for The BrainHealth Project at the University of Texas at Dallas' Center for BrainHealth. For starters, she's not even sure if 10% refers to volume or something else: "Is it 10% of energy metabolism? Is it 10% of electrical activity? Is it blood oxygenation levels?" This myth is so pervasive that students ask about it. "In my classes, whenever anybody brings up that myth, I say, 'If you're only using 10% of your brain, you're probably hooked up to a ventilator,'" Hecht said.

Related: Why do our brains have folds?

Hecht likened brain activity to the heart when the body is at rest; the heart keeps pumping even if it's not working to its fullest capacity. Likewise, the entire brain and its cells, called neurons, are always active even just at a baseline level. "Neurons have to fire at some sort of baseline level in order to keep themselves healthy," she said.

According to Fratantoni and Hecht, while the brain is classified into discrete regions, the organ operates via various networks. No single region ever acts in isolation. Fratantoni gave the example of the default mode network, which involves several cognitive areas to process thought and social interactions.

So, how do we know which parts of the brain are active? The best tool we have to measure brain activity is functional magnetic resonance imaging (fMRI). This neuroimaging technique requires someone to lie in a tube-like scanner while responding to different stimuli. The scanner measures blood flow changes in the brain, which indicates increased energy use in different regions. 

"The idea is that parts of the brain that are receiving more blood are burning more energy, and therefore, they're more functionally involved with whatever you're thinking about," Hecht said.

Our brains recruit fewer resources for skills we know well. When we practice a skill, our brains change in a few observable ways. First, brain tissue associated with that skill's regions physically enlarges, according to Hecht. She says researchers hypothesize this growth may come from neurons branching out to connect with neighboring neurons, or from increased vascularization that would facilitate more blood flow. At the same time, the more practiced the brain becomes at a skill, the more efficient it is and the less energy it requires. 

"As you become more proficient at something that you're learning to do, less of your brain is active," Hecht said. 

Mental energy, or conscious effort expended to complete a task, is another effective way for individuals to measure their personal brain use, Fratantoni said. Because one can't scientifically test mental energy, this metric allows for subjectivity. 

"What I guess would be a better way to think about it is, do you even know what your capacity is?" she told Live Science. "What could you be doing to reach more of your fuller potential?" In Hecht's view, the answer is to diligently practice whatever skill you're cultivating. 

Ultimately, the notion of using 10% of the brain is not only incorrect, but irrelevant. Hecht mentioned that after a debilitating injury or stroke, some people can restrengthen abilities "with other parts of the brain kind of taking over the function" that the damaged region had controlled. The incredibly plastic mind can rewire itself when a region is lost or damaged, so what comprises 100% can change. Even with a portion of the brain injured or removed, every mind can find a way to work at its fullest capacity.

You're walking somewhere you've never been before and suddenly feel as though you've strolled down the same road already. You're experiencing the well-known phenomenon déjà vu — but what is déjà vu, really, and why does the strange feeling happen?

Déjà vu is a French expression meaning "already seen," which was first used in 1876 by French philosopher Émile Boirac in a letter to his book editor, and later in his published book "The Psychology of the Future" (Keagan Paul, 1918). 

Déjà vu is the feeling that something a person is currently experiencing has already occurred in the past. Experts refer to this phenomenon as a memory illusion involving familiarity and unfamiliarity, according to the book "Psychology of Learning and Motivation" (Elsevier, 2010). The illusion pits a person's impression that an experience is familiar against their knowledge that this sense of familiarity is inaccurate. An estimated two-thirds of people report experiencing déjà vu, the book states, and the frequency of reported episodes decreases with age.

Related: How does the brain store memories? 

Some people report experiencing déjà vu to a frequent degree that's disturbing to them. Such cases can be caused by substance abuse, migraine and anxiety, reports suggest, as well as depersonalization-derealization, a mental condition where a person feels detached from their body or surroundings. However, temporal lobe epilepsy is thought to be the most common cause of such frequent déjà vu. Scientists suggest that, at least in epilepsy, déjà vu episodes may arise from seizures in the brain's temporal lobe or dysfunction in brain regions involved in storing and retrieving memory, like the hippocampus and parahippocampus.  

However, given that déjà vu is also experienced by individuals without epilepsy or other conditions, there must be other explanations as to why the bizarre experience occurs.

"One possible mechanism is the memory-based theory which focuses on the role of familiarity and recognition in déjà vu," Dr. Ooha Susmita, an in-house neuropsychiatrist at Allo Health, told Live Science. This theory suggests that "Déjà vu arises when a current situation strongly resembles a previously encountered but forgotten experience," Susmita said. 

"The new situation may share similarities with a past event, leading to a sense of familiarity without an accompanying memory of the specific details." She added that déjà vu may result from our brain's attempt to make sense of these perceived similarities and create a feeling of recognition, even if we cannot consciously recall the original experience.

Historically, scientists have struggled to recreate déjà vu in the laboratory because it's difficult to identify stimuli that can evoke the feeling. But they've found ways around this challenge. (For example, in 2010, University of Leeds researchers even reported using hypnosis to induce déjà vu in volunteers.)

In a study published in 2012 in the journal Consciousness and Cognition, Anne Cleary, a professor of cognitive psychology at Colorado State University, and her team used virtual reality (VR) to investigate the hypothesis that people may experience déjà vu when they encounter environmental layouts that are similar to those experienced in the past, provided that they don't recall that past experience. This is called the "Gestalt familiarity hypothesis," built on the arrangement of items in an environment.  

In their experiment, Cleary and her team attempted to trigger déjà vu in participants by having them navigate different scenes with a VR headset; some scenes shared the same spatial layout, meaning their walls and furniture were placed in the same locations, for example. The team found that people were more likely to report feelings of déjà vu when they found themselves in settings with a similar design to scenes they have seen in the past but didn't specifically recall.  

Another theory suggests that déjà vu results from perceptual gap, or split perception, according to "Psychology of Learning and Motivation." Split perception occurs when the brain processes the same sensory signals twice, back to back, at a particular moment. In the initial process, the signal is brief and often goes unnoticed in the conscious mind. During the second process, which follows almost immediately, feelings of familiarity (déjà vu) are established due to that first signal, which cannot be recalled. 

In 2016, Akira O'Connor, a lecturer at the school of psychology and neuroscience at the University of St. Andrews in Scotland, presented research that suggested that déjà vu is caused by the brain correcting memory errors, New Scientist reported. 

O'Connor and his team used a brain scanning technique called functional resonance magnetic imaging (fMRI) to check which parts of the brain are active when déjà vu is triggered in the lab. From their result, it was not the hippocampus, a key brain region responsible for memory retrieval, that was active, but the medial prefrontal cortex, a region involved in resolving conflicts between what we remember experiencing and what we've actually experienced. 

According to O'Connor, this region of the brain shoots off a signal when such a mismatch occurs, and this may explain why déjà vu is more common in young people than old. As a person gets older, déjà vu is not as frequent because "the general checking system is in decline," he told New Scientist, making it difficult for them to discern false memories.     

There is no universally agreed upon scientific theory that explains the mechanism behind déjà vu. More research is needed to explain this mysterious sensation, Susmita told Live Science.

"It is important to note that déjà vu is a common experience and is not considered to be a sign of any underlying medical or psychological condition," Susmita said. "While our understanding of déjà vu has advanced over the years, it remains a complex and intriguing phenomenon that continues to be the subject of scientific inquiry. Further research is needed to unravel the precise mechanisms involved in déjà vu."