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.

Astrology has a long history, stretching back thousands of years and permeating across numerous ancient civilizations. In modern times, astrology is big business — and it's growing. In 2025, the industry was estimated to be worth around $3 billion.

In this excerpt from "What Science Says About Astrology" (Columbia University Press, 2026), author and science journalist Carlos Orsi looks at a study of 20 million people that sought to test whether star signs have a role in romantic compatibility.

The most robust use of data to test astrology is the study of love signs conducted by David Voas in 2007, involving data from more than 20 million people from the 2001 census from England and Wales. Voas tested the hypothesis that certain sun signs were "more compatible" for romantic relationships.

The use of the supposed romantic compatibility/incompatibility between signs or planetary configurations to test astrology's validity has a long history. This strategy was, for example, employed by Carl Jung (1875–1967) in his work on astrology and synchronicity and in the classic study by Bernie Silverman.

The idea of astrological compatibility or incompatibility in love has strong popular appeal. The book "Love Signs", by Linda Goodman (1925–1995), an almost 1,000-page tome, continues to be reprinted and sold 30 years after the author's death (as of this writing, the most recent edition dates from 2020). In general, signs separated on the zodiac wheel by angles of 60° and 120° are considered favorable for love, while those separated by 180° are seen as extremely incompatible. Right angles also tend to be interpreted as bad omens.

Voas explains the rationale of his study this way: People born during the month-long periods defined by a particular sun sign are supposed to share certain dispositions, for example, to be generous or sensitive or stubborn. These tendencies affect personal relationships.

We know from everyday experience as well as a mass of social scientific data that people who are similar in age, education, social class, religion, ethnicity and so on are far more likely to marry than those who are different in these respects. Couples are regarded as being well or poorly matched on the basis of appearance or personality. If astrological compatibility exists, its effects should be observable.

This last point — that the effects should be observable — is crucial. Astrologers often complain that tests based solely on sun signs are unfair because a sun sign's influence represents only a fraction of an entire birth chart's meaning. However, a sample of 20 million people, like Voas's, neutralizes this objection.

Even if the sun sign accounts for only, say, 0.1% of overall romantic compatibility, in a sample composed of 10 million couples, this should result in an excess of 10,000 formed by people with compatible signs, above and beyond what would be expected if astrology had no effect. Or, as the author states, "With a sufficiently large sample, we should be able to detect any tendency for some signs to attract or repel each other."

The study's initial goal was to find an excess of pairings between signs deemed compatible by the consensus of astrological literature. Unfortunately, Voas writes, such a consensus was hard to find: "There is no great consistency among astrologers, and a survey of books and websites reveals a considerable variety of views concerning propitious pairings." So he opted for the least common denominator, searching for any deviation from basic probability: "In this research I look for evidence that any combination of signs is found more or less often than would be expected to occur by chance."

The results were at least intriguing: The initial analysis indicated an excess of couples where both partners had the same sign or adjacent signs — e.g., more Capricorns with Capricorns or Capricorns with Aquarians than expected. There were about 22,000 extra couples with matching signs beyond what chance would predict and an additional 5,000 couples with adjacent signs. Could this be astrology in action?

Voas dug deeper into the data and discovered more anomalies. For example, the excess of couples born in the same month was even greater (23,000) than that of couples with the same sign, and the proportion of couples with the same birth date was 41% higher than expected by chance. "Now while there may be some people who are drawn to each other because they share a birthday, the excess probably reflects response error for the most part," he wrote. "Census forms are typically completed by one member of the household, and that individual may — through carelessness or forgetfulness — write in his or her birthday when entering details for the spouse."

Other statistical anomalies attributed to errors include an excess of birth dates recorded as January 1 (probably a placeholder when the actual date is unknown), instances of matching days in different months, and matching months with different days. Voas's challenge, then, was distinguishing these potential data entry errors from any real astrological effect — if one existed.

"The partial overlap between astrological signs and months of birth allows a crucial test," he wrote, noting that the first 10 days of the period covered by any sign falls in one month while the other 20 or so fall in the next (for example, Aries runs from March 21 to April 20). So was a person born in the last days of March more likely to be married to someone born in the early weeks of March or perhaps the early weeks of April? In the first case, their spouse would be from the same month but a different sign; in the second, from a different month but the same sign.

"The results were conclusive. The couples whose birthdays belonged to the same sign but fell in different months were no more numerous than chance would dictate. By contrast, there were more combinations of birthdays from different parts of the same month than expected. This excess in shared months of birth is probably the result of response error, but in any event sun sign is not a factor."

The slight excess of couples with adjacent signs was explained by a data-imputation technique used in the British census to fill in missing or illegible data. One partner's birth date was imputed as the first day of a month and the other's as the first of the following month. When these imputed data points were excluded from the sample, the "adjacent sign" effect disappeared. The bottom line is that an analysis of 10 million couples in England and Wales revealed no astrological effect.

But Voas's work illustrates how easy it is to get lost in data or be swayed by enthusiasm. Someone who had stopped at the first step — finding an excess of couples with the same sign — might have mistakenly presented census data as validation for astrology.

This article is excerpted from What Science Says About Astrology by Carlos Orsi. Copyright (c) 2026 Columbia University Press. Used by arrangement with the Publisher. All rights reserved.

A college student has created a prototype polish to turn a fingernail into a touch-screen stylus, after noticing that people with long nails and calloused fingertips struggled to work their smartphones.

Manasi Desai, a student at Centenary College of Louisiana with an interest in cosmetic chemistry, launched the project with her research supervisor, Joshua Lawrence, an associate professor of chemistry at Centenary. Their goal was to create a clear, nontoxic polish that would allow a nail to access a touch screen the way a human fingertip does.

"Our final, clear polish could be put over any manicure or even bare nails, which could help people with calluses on their fingertips too," Desai said in a statement. "So it has both a cosmetic and lifestyle benefit."

Desai and Lawrence presented their research Monday (March 23) at the annual meeting of the American Chemical Society.

Who needs touchscreen polish?

While touch screens are nearly ubiquitous today, some people cannot use them as easily as others. For example, guitar players and carpenters with callouses on their fingers may be unable to get the screen to register their touch because their fingertip skin prevents electrical flow ‪—‬ a problem Consumer Reports called "zombie finger" in 2015. But touch screens are also difficult to use when a person's hand is gloved, is very dry or has long nails.

After the researchers asked a phlebotomist with long nails who was struggling to operate a smartphone whether touch-screen-compatible nail polish would be useful — and got a resounding "Yes" answer — they set out to develop a new product.

"Chemists are here to solve problems and to try to make your world better," Lawrence said in the statement.

The touch screens in modern tablets and smartphones work through a property called capacitance. A small electric field is created on the screen, and when a conductive material, like a finger, touches the surface, the electric field is interrupted. The screen registers the disruption — a change in capacitance — as a touch at a particular location. But tapping the screen with a nonconductive material, like a fingernail, does not register as a touch.

Previous researchers' attempts at creating a capacitive nail polish focused on including carbon nanotubes or metallic particles to make the fingernail electrically conductive. However, these particles are dangerous if inhaled and limit the color range of polishes.

For her project, Desai methodically tested combinations of 13 commercially available clear-coat nail polishes and more than 50 additives to find one that met three criteria: It was clear, it was nontoxic and it created a conductive top coat.

In her experiments, Desai found that the polishes that performed best included the amino acid taurine and the organic molecule ethanolamine, an amino alcohol. When combined, the taurine and ethanolamine additives created a formula that registered as a touch on a smartphone.

The new polish formula was designed to work through acid-base chemistry rather than the inclusion of metal additives. With acid-base chemistry, acids donate protons and bases accept protons.

"We think that the materials we are producing are working via protons hopping from acidic to basic groups," Lawrence told Live Science in an email, because the mixture of taurine and ethanolamine — an ammonium acid and an amine base — works well. "We think we have proton exchange between acidic and basic groups at the surface of the polish, fulfilling the same role as ion mobility in skin," Lawrence said.

It will be a while before their polish hits store shelves, though. The nail polish does not work long enough yet. "All our formulations lose efficacy too quickly," Lawrence said. "They stop working after hours or days, and we want them to work for days or weeks, minimum."

Desai and Lawrence are working on tweaking their formula to find the best-performing combination of ingredients and to make the current formulation nontoxic. Currently, the least-toxic formulation they devised results in a gritty, speckled finish ‪—‬ "not high fashion to be sure," Lawrence said.

The researchers have already submitted a provisional patent for their invention. "Right now, we have a good proof of concept material, but need to do a lot more work!" Lawrence said.

Periodic table of elements quiz: How many elements can you name in 10 minutes?

If you love puzzles and science, you've come to the right place. With our new daily puzzle, you have six attempts to guess the science word of the day and complete the word chain.

After every guess, letters that appear in the word will get a yellow chain link, and if they're in the right place the link will go green. Get them all right and you'll earn a space on our leaderboard.

Let us know how you scored by leaving a comment below (but no spoilers please), and be sure to check back every day for a new word. Good luck!

We've all seen it: a kid with one finger wedged up a nostril, mining the cavity for a golden nugget, teasing it out, and then gobbling it like a tasty snack. It may be gross to adults, but most children seem completely unfazed. So why do kids eat their boogers, and are they possibly onto something?

Most parents will tell you how common it is for children to eat their own mucus — a behavior known as "mucophagy" — yet data on its prevalence are scarce.

One survey suggests that nose picking overall isn't limited to kids; adults commonly do it, too. Another 2001 study based on a survey of 200 teenagers in India found that almost all participants admitted to picking their noses; what's more, nine in the sample said they routinely ate the boogers. As for the question of why kids eat their own mucus, there haven't been any rigorous investigations.

However, researchers have found that mucophagy is shared by at least 12 other primate species.

Evolutionary biologist Anne-Claire Fabre first discovered this when watching the aye-aye (Daubentonia madagascariensis). This lemur species is known for its 3-inch-long (8 centimeters) middle finger, which it uses to pry insects out of hard-to-reach crevices. But when Fabre was watching a captive aye-aye in 2015, she was surprised to see it sticking that long, thin digit into its nostrils; extracting mucus; and then licking its finger clean.

"It was hilarious and disgusting at the same time," recalled Fabre, an associate professor at the University of Bern in Switzerland. "It seemed that it was really enjoying what it was doing. It's something that they do pretty often." (It's possible that the captive aye-aye was unusual in its nose-picking habit, but there's no reason to assume this doesn't also happen in wild aye-ayes, Fabre said.)

This made Fabre wonder if other primates eat their mucus, too. When she carried out a literature review that included her own observations of the aye-aye, she found evidence that gorillas, bonobos, chimpanzees, macaques, capuchins and other primates also pick their noses and eat the mucus. Most species used their fingers, but some used sticks to pry out the spoils. Some primates even extended the favor, picking others' noses too, the research found.

"When you see the composition of mucus, it's mostly water, at more than 98%," Fabre said. The remainder is composed of a protein-carbohydrate ingredient called mucins, and salts. It's possible that animals reap some benefit from consuming these ingredients, the way that some species will eat their own feces to digest the remaining nutrients there, Fabre explained.

This idea raises the question of whether there may be a deeper evolutionary basis for mucophagy in humans.

Mucus creates a protective layer that traps dust, spores and disease-causing microorganisms as we inhale, before it reaches the lungs. In 2013, a biochemist shared a hypothesis that eating boogers could therefore expose children to small doses of pathogens that train the immune system to identify these molecules and can help to trigger an immune response. However, this idea was not ultimately tested in empirical research.

Dr. Chittaranjan Andrade, author of the 2001 nose-picking study in teenagers, is wary about such theories. "I am skeptical. Any immune substance that survives drying in the mucus is likely to be very small in quantity, and it is also likely to be digested after ingestion," therefore likely having a limited effect, the senior professor emeritus at the National Institute of Mental Health and Neurosciences in Bangalore, India, explained in an email.

Other experts have cautioned that because nasal mucus can spread pneumonia-causing bacteria, nose picking and mucophagy in children should be controlled when they are around immunocompromised people.

With no evidence behind the idea that mucophagy boosts immunity, researchers have looked for more intuitive reasons why kids eat their own mucus. Boogers can create itching, tightness, and discomfort in the nose that might prompt nose-picking, and curious children might then give it a taste-test, Fabre suspects.

One researcher asked children directly why they ate their boogers. The results were published in a 2009 book chapter that was not peer-reviewed and were based on a very small sample of just 10 children. But their insights included the fact that they liked eating boogers simply because of their appealing texture and taste.

Andrade believes that children develop this habit because it doesn't yet have the negative association that it carries for older people. "Because [children] do it openly, they are observed and scolded, and because the act, picking as well as eating, is stigmatized, my guess is that they do not repeat it, not openly anyway," Andrade said.

Until there's concrete research into the question, the answer to precisely why children eat their boogers will remain elusive. To Fabre at least, it's a topic that deserves more investigation to understand if there are possible benefits or harms of mucophagy to child development.

Ultimately, she takes kids at their word and believes that they may eat their boogers simply because they like it. "It's something that is crunchy and a little bit salty," she says. And having watched nose-picking aye-ayes for hours and learned about the prevalence of this habit in other species, it no longer gives Fabre the ick: "Honestly, in my opinion, it's not something that is disgusting."

The world of science news never sleeps, but even we need to take a break every now and then. And what better way than to give our collective brains a good workout with sudoku?

The rules are simple: Each row, column and 3 x 3 box must contain the numbers 1 to 9, with no repeats. Sounds simple, right? Sometimes it is; other times, it's a little more challenging. (That's when tapping the hints button comes in handy.) Regardless, it's a great way to step back for a bit and crunch some numbers.

We have three new sudoku puzzles of varying difficulties every day — easy, medium and hard — so be sure to bookmark this page and try a new challenge. Enjoy!

Easy, 36-45 clues

Medium, 28-35 clues

Hard, 17-27 clues

More quizzes and games

From beginning to end, 2025 was a year of devastation for scientists in the United States.

January saw the abrupt suspension of key operations across the National Institutes of Health, not only disrupting clinical trials and other in-progress studies but stalling grant reviews and other activities necessary to conduct research. Around the same time, the Trump administration issued executive orders declaring there are only two sexes and ending DEI programs. The Trump administration also removed public data and analysis tools related to health disparities, climate change and environmental justice, among other databases.

February and March saw a steep undercutting of federal support for the infrastructure crucial to conducting research as well as the withholding of federal funding from several universities.

And over the course of the following months, billions of dollars of grants supporting research projects across disciplines, institutions and states were terminated. These include funding already spent on in-progress studies that have been forced to end before completion. Federal agencies, including NASA, the Environmental Protection Agency, the National Oceanic and Atmospheric Administration and the U.S. Agency for International Development have been downsized or dismantled altogether.

The Conversation asked researchers from a range of fields to share how the Trump administration’s science funding cuts have affected them. All describe the significant losses they and their communities have experienced. But many also voice their determination to continue doing work they believe is crucial to a healthier, safer and more fair society.

Pipeline of new scientists cut off

Carrie McDonough, Associate Professor of Chemistry, Carnegie Mellon University

People are exposed to thousands of synthetic chemicals every day, but the health risks those chemicals pose are poorly understood. I was a co-investigator on a US $1.5 million grant from the EPA to develop machine-learning techniques for rapid chemical safety assessment. My lab was two months into our project when it was terminated in May because it no longer aligned with agency priorities, despite the administration’s Make America Healthy Again report specifically highlighting using AI to rapidly assess childhood chemical exposures as a focus area.

Labs like mine are usually pipelines for early-career scientists to enter federal research labs, but the uncertain future of federal research agencies has disrupted this process. I’m seeing recent graduates lose federal jobs, and countless opportunities disappear. Students who would have been the next generation of scientists helping to shape environmental regulations to protect Americans have had their careers altered forever.

I’ve been splitting my time between research, teaching and advocating for academic freedom and the economic importance of science funding because I care deeply about the scientific and academic excellence of this country and its effects on the world. I owe it to my students and the next generation to make sure people know what’s at stake.

Fewer people trained to treat addiction

Cara Poland, Associate Professor of Obstetrics, Gynecology and Reproductive Biology, Michigan State University

I run a program that has trained 20,000 health care practitioners across the U.S. on how to effectively and compassionately treat addiction in their communities. Most doctors aren’t trained to treat addiction, leaving patients without lifesaving care and leading to preventable deaths.

This work is personal: My brother died from substance use disorder. Behind every statistic is a family like mine, hoping for care that could save their loved one’s life.

With our federal funding cut by 60%, my team and I are unable to continue developing our addiction medicine curriculum and enrolling medical schools and clinicians into our program.

Meanwhile, addiction-related deaths continue to rise as the U.S. health system loses its capacity to deliver effective treatment. These setbacks ripple through hospitals and communities, perpetuating treatment gaps and deepening the addiction crisis.

Communities left to brave extreme weather alone

Brian G. Henning, Professor of Philosophy and Environmental Studies and Sciences, Gonzaga University

In 2021, a heat dome settled over the Northwest, shattering temperature records and claiming lives. Since that devastating summer, my team and I have been working with the City of Spokane to prepare for the climate challenges ahead.

We and the city were awarded a $19.9 million grant from the EPA to support projects that reduce pollution, increase community climate resilience and build capacity to address environmental and climate justice challenges.

As our work was about to begin, the Trump administration rescinded our funding in May. As a result, the five public facilities that were set to serve as hubs for community members to gather during extreme weather will be less equipped to handle power failures. Around 300 low-income households will miss out on efficient HVAC system updates. And our local economy will lose the jobs and investments these projects would have generated.

Despite this setback, the work will continue. My team and I care about our neighbors, and we remain focused on helping our community become more resilient to extreme heat and wildfires. This includes pursuing new funding to support this work. It will be smaller, slower and with fewer resources than planned, but we are not deterred.

LGBTQ+ people made invisible

Nathaniel M. Tran, Assistant Professor of Health Policy and Administration, University of Illinois Chicago

This year nearly broke me as a scientist.

Shortly after coming into office, the Trump administration began targeting research projects focusing on LGBTQ+ health for early termination. I felt demoralized after receiving termination letters from the NIH for my own project examining access to preventive services and home-based care among LGBTQ+ older adults. The disruption of publicly funded research projects wastes millions of dollars from existing contracts.

Then, news broke that the Centers for Disease Control and Prevention would no longer process or make publicly available the LGBTQ+ demographic data that public health researchers like me rely on.

But instead of becoming demoralized, I grew emboldened: I will not be erased, and I will not let the LGBTQ+ community be erased. These setbacks renewed my commitment to advancing the public’s health, guided by rigorous science, collaboration and equity.

Pediatric brain cancer research squelched

Rachael Sirianni, Professor of Neurological Surgery, UMass Chan Medical School

My lab designs new cancer treatments. We are one of only a few groups in the nation focused on treating pediatric cancer that has spread across the brain and spinal cord. This research is being crushed by the broad, destabilizing impacts of federal cuts to the NIH.

Compared to last year, I am working with around 25% of our funding and less than 50% of our staff. We cannot finish our studies, publish results or pursue new ideas. We have lost technology in development. Students and colleagues are leaving as training opportunities and hope for the future of science dries up.

I’m faced with impossible questions about what to do next. Do I use my dwindling research funds to maintain personnel who took years to train? Keep equipment running? Bet it all on one final, risky study? There are simply no good choices remaining.

Inequality in science festers

Stephanie Nawyn, Associate Professor of Sociology, Michigan State University

Many people have asked me how the termination of my National Science Foundation grant to improve work cultures in university departments has affected me, but I believe that is the wrong question. Certainly it has meant the loss of publications, summer funding for faculty and graduate students, and opportunities to make working conditions at my and my colleagues’ institutions more equitable and inclusive.

But the greatest effects will come from the widespread terminations across science as a whole, including the elimination of NSF programs dedicated to improving gender equity in science and technology. These terminations are part of a broader dismantling of science and higher education that will have cascading negative effects lasting decades.

Infrastructure for knowledge production that took years to build cannot be rebuilt overnight.

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.

In 1910, a fierce competition began between Norwegian explorer Roald Amundsen and British captain Robert Falcon Scott. Each explorer wanted to be first to reach the geographic South Pole, thereby vanquishing the last unexplored continent on Earth. The race was destined to end in tragedy.

Scott previously attempted to conquer the southernmost continent in 1902, but he had to turn back due to ill health and unfavorable temperatures. His crew, most of whom came from Ernest Shackleton's recently returned Nimrod, set sail from Cardiff, Wales, on June 15, 1910.

Amundsen, meanwhile, played his cards close to the vest. He, too, wanted to be the first to reach a pole, and he had originally set his sights on the North Pole. He quietly changed plans in 1909 after Matthew Henson and Robert Peary, along with four Inuit assistants, beat him to it.

Amundsen set sail from Norway on Aug. 9, 1910, aboard the Fram, which had previously been used on two key expeditions — one drifting over the Arctic Ocean and another exploring what is now Nunavut, Canada. Amundsen kept his plans secret from all but three of his crew members until he reached the Portuguese island of Madeira in September.

At that point, he told the crew and messaged his rival. "Beg leave to inform you Fram proceeding Antarctic. Amundsen," he said in his telegram to Scott, according to the Antarctic Heritage Trust. The message was waiting for Scott when he arrived in October in Melbourne, Australia.

By early 1911, Scott had set up his base in McMurdo Sound, while Amundsen sailed into the Bay of Whales and established his base, Framheim, on the Ross Ice Shelf. This put Amundsen a crucial 60 miles (100 kilometers) closer to the geographic South Pole.

After an initial, unsuccessful exploratory foray, Amundsen returned to Framheim and regrouped. He split up his team, with one group setting off for the South Pole and another exploring a separate region. On Oct. 21, Amundsen and crew members Olav Bjaaland, Oscar Wisting, Helmer Hanssen and Sverre Hassel set off from Framheim on four sleds, each of which was pulled by 13 dogs.

On Dec. 14, at 3 p.m. local time, Amundsen shouted "Halt!"

They believed they'd reached the South Pole, and they soon set up a tent and planted the Norwegian flag.

Scott arrived 35 days later to find Amundsen's tent and Norwegian flag. He and his crew would perish on the return journey, due to starvation, dehydration and exposure to extreme cold.

In his last journal entry on March 29, Scott wrote, "I do not think we can hope for any better things now. We shall stick it out to the end, but we are getting weaker, of course, and the end cannot be far. It seems a pity, but I do not think I can write more." They were just 11 miles (17 km) from their next supply cache. Their bodies were found in November, 1912.

Why did Amundsen's crew succeed where Scott did not? A few details may have made a difference. Amundsen took a shorter route over the Axel Glacier. He also dressed his crew in the traditional Inuit garb, whereas Scott's team wore wool clothes. They also ruthlessly reduced the weight of their sleds and organized their supplies so they could reach them with minimal exposure to cold temperatures.

Finally, Amundsen devised a plan to shoot and eat the sled dogs along the way to supplement their relatively meager food supplies, and they ate raw penguin meat, which provides the vitamin C crucial to staving off scurvy. All of these factors may have helped him arrive more quickly and return safely.

Early accounts painted Scott's failure as one of ineptitude, but recent evidence suggests he may have simply fallen prey to unusually severe weather — and possibly the malfeasance of his crew. A 2017 article in the journal Polar Record suggested that crew member Edward Evans may have contributed to the team's failure by taking more than his fair share of food, leaving shortages at key depots. He also may have failed to pass on orders, such as the placement of sled dogs at critical junctures, which could have led to the team's demise.

Just a few years later, Shackleton helmed the Endurance as part of an attempt to cross the coldest continent on foot. The effort famously failed; the ship sank, and its crew became stranded on Elephant Island. But incredibly, all of the crew members survived for four months and were rescued in August 1916 after Shackleton left to seek help.

Nowadays, the South Pole is home to the Amundsen-Scott South Pole Station, as well as the IceCube Neutrino Observatory and the South Pole Telescope.

"Time flies," "time waits for no one," "as time goes on": The way we speak about time tends to strongly imply that the passage of time is some sort of real process that happens out there in the world. We inhabit the present moment and move through time, even as events come and go, fading into the past.

But go ahead and try to actually verbalize just what is meant by the flow or passage of time. A flow of what? Rivers flow because water is in motion. What does it mean to say that time flows?

Events are more like happenings than things, yet we talk as though they have ever-changing locations in the future, present or past. But if some events are future, and moving toward you, and some past, moving away, then where are they? The future and past don't seem to have any physical location.

Human beings have been thinking about time for as long as we have records of humans thinking about anything at all. The concept of time inescapably permeates every single thought you have about yourself and the world around you. That's why, as a philosopher, philosophical and scientific developments in our understanding of time have always seemed especially important to me.

Ancient philosophers on time

Ancient philosophers were very suspicious about the whole idea of time and change. Parmenides of Elea was a Greek philosopher of the sixth to fifth centuries BCE. Parmenides wondered, if the future is not yet and the past is not anymore, how could events pass from future to present to past?

He reasoned that, if the future is real, then it is real now; and, if what is real now is only what is present, the future is not real. So, if the future is not real, then the occurrence of any present event is a case of something inexplicably coming from nothing.

Parmenides wasn't the only skeptic about time. Similar reasoning regarding contradictions inherent in the way we talk about time appears in Aristotle, in the ancient Hindu school known as the Advaita Vedanta and in the work of Augustine of Hippo, also known as St. Augustine, just to name a few.

Einstein and relativity

The early modern physicist Isaac Newton had presumed an unperceived yet real flow of time. To Newton, time is a dynamic physical phenomenon that exists in the background, a regular, ticking universe-clock in terms of which one can objectively describe all motions and accelerations.

Then, Albert Einstein came along.

In 1905 and 1915, Einstein proposed his special and general theories of relativity, respectively. These theories validated all those long-running suspicions about the very concept of time and change.

Relativity rejects Newton's notion about time as a universal physical phenomenon.

By Einstein's era, researchers had shown that the speed of light is a constant, regardless of the velocity of the source. To take this fact seriously, he argued, is to take all object velocities to be relative.

Nothing is ever really at rest or really in motion; it all depends on your "frame of reference." A frame of reference determines the spatial and temporal coordinates a given observer will assign to objects and events, on the assumption that he or she is at rest relative to everything else.

Someone floating in space sees a spaceship going by to the right. But the universe itself is completely neutral on whether the observer is at rest and the ship is moving to the right, or if the ship is at rest with the observer moving to the left.

This notion affects our understanding of what clocks actually do. Because the speed of light is a constant, two observers moving relative to each other will assign different times to different events.

In a famous example, two equidistant lightning strikes occur simultaneously for an observer at a train station who can see both at once. An observer on the train, moving toward one lightning strike and away from the other, will assign different times to the strikes. This is because one observer is moving away from the light coming from one strike and toward the light coming from the other. The other observer is stationary relative to the lightning strikes, so the respective light from each reaches him at the same time. Neither is right or wrong.

How much time elapses between events, and what time something happens, depends on the observer's frame of reference. Observers moving relative to each other will, at any given moment, disagree on what events are happening now; events that are happening now according to one observer's reckoning at any given moment will lie in the future for another observer, and so on.

Under relativity, all times are equally real. Everything that has ever happened or ever will happen is happening now for a hypothetical observer. There are no events that are either merely potential or a mere memory. There is no single, absolute, universal present, and thus there is no flow of time as events supposedly "become" present.

Change just means that the situation is different at different times. At any moment, I remember certain things. At later moments, I remember more. That's all there is to the passage of time. This doctrine, widely accepted today among both physicists and philosophers, is known as "eternalism".

This brings us to a pivotal question: If there is no such thing as the passage of time, why does everyone seem to think that there is?

Time as a psychological projection

One common option has been to suggest that the passage of time is an "illusion" — exactly as Einstein famously described it at one point.

Calling the passage of time "illusory" misleadingly suggests that our belief in the passage of time is a result of misperception, as though it were some sort of optical illusion. But I think it's more accurate to think of this belief as resulting from misconception.

As I propose in my book "A Brief History of the Philosophy of Time," our sense of the passage of time is an example of psychological projection — a type of cognitive error that involves misconceiving the nature of your own experience.

The classic example is color. A red rose is not really red, per se. Rather, the rose reflects light at a certain wavelength, and a visual experience of this wavelength may give rise to a feeling of redness. My point is that the rose is neither really red nor does it convey the illusion of redness.

The red visual experience is just a matter of how we process objectively true facts about the rose. It's not a mistake to identify a rose by its redness; the rose enthusiast isn't making a deep claim about the nature of color itself.

Similarly, my research suggests that the passage of time is neither real nor an illusion: It's a projection based on how people make sense of the world. I can't really describe the world without the passage of time any more than I can describe my visual experience of the world without referencing the color of objects.

I can say that my GPS "thinks" I took a wrong turn without really committing myself to my GPS being a conscious, thinking being. My GPS has no mind, and thus no mental map of the world, yet I am not wrong in understanding its output as a valid representation of my location and my destination.

Similarly, even though physics leaves no room for the dynamic passage of time, time is effectively dynamic to me as far as my experience of the world is concerned.

The passage of time is inextricably bound up with how humans represent our own experiences. Our picture of the world is inseparable from the conditions under which we, as perceivers and thinkers, experience and understand the world. Any description of reality we come up with will unavoidably be infused with our perspective. The error lies in confusing our perspective on reality with reality itself.

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

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.

"Science is never settled" has become a go-to slogan for populists seeking to legitimise politically convenient but fringe scientific positions. In 2020, MAGA Republican Representative Nancy Mace was asked whether she agreed that climate change is the result of humanmade greenhouse emissions. She responded: "My opponent has said that the science is settled on this. Well, the science is never settled. Scientists will tell you that."

In February, Senator Roger Marshall argued more money should be spent on investigating widely debunked links between autism and vaccines, saying "I'm a physician. Science is never settled. That's what makes us scientists."

The phrase has also crossed the Atlantic. When asked if President Donald Trump was right to share widely debunked claims about a link between Tylenol use in pregnancy and autism, U.K. Reform party leader Nigel Farage replied, "I have no idea." When pressed on whether he would "side with medical experts who say it's dangerous nonsense," he responded, "When it comes to science, I don't side with anybody… because science is never settled."

The issue is, of course, that in many areas, from the theory of evolution to the theory of gravity, science is very much settled. To pretend otherwise is to misrepresent the position of the scientific community.

That doesn't mean that scientific positions are eternally fixed and can't be updated in light of new evidence. It means that our current best explanations have been tested enough for us to be confident that they are good descriptions of the way things work.

Myth of overturned consensus

A favorite trope of climate denialists is that scientists in the 1970s predicted "global cooling" — an imminent ice age. It's a smart argument, because if you can suggest that the exact opposite of global warming was once the prevailing view, surely you throw the current consensus on climate science into doubt?

Despite media attention and much discussion of the idea, global cooling was never a consensus scientific position. Reviews of the literature at the time show that even 50 years ago, global warming dominated scientific thinking about the Earth's short-term climate future. That climate change is the result of greenhouse gas emissions is now very much the consensus scientific position.

There are, however, examples in science where consensus positions have been modified or updated. Gravity is a classic case. Galileo established that acceleration due to gravity is the same for all objects near Earth's surface. But it wasn't until Newton that we had a universal theory of gravitation.

Newton's theory unified the behavior of objects falling on earth with the motions of planets. For years, every measurement seemed to confirm it, and the theory became known as a "law" that nature was thought to obey without exception.

But as experiments expanded and instruments improved, the edges of Newton's "law" began to fray. When dealing with strong gravitational fields like those near a black hole, or when calculating to high precision or over short astronomical distances, Newton's law wasn't sufficient. In the 20th century, Einstein's general relativity filled many gaps — resolving a range of seeming astronomical anomalies and describing how light bends near a black hole.

Yet even the relativistic interpretation of gravity is not perfect. We know, for example, that it must break down inside a black hole.

First Galileo's and then Newton's theories were superseded, and we know Einstein's isn't correct in every situation. Does that mean these earlier theories are useless and not examples of settled science? Definitely not.

In contexts where these theories have been rigorously tested and shown to give the correct answers (to a given degree of precision), they remain valid. They aren't wrong — just special cases of the more general theories, valid within a given domain of legitimacy in which they were originally postulated and tested.

In the same way, whatever supersedes Einstein's theory will have to include it as a special case. The example of gravity shows that scientific knowledge can evolve yet still be considered settled within its domain of legitimacy. We can point to other consensuses, like evolution or germ theory, as settled science that has been expanded and generalized over time.

Scientific 'facts'

There are also questions that most would call definitively settled. That Earth is round, not flat, is perhaps the most obvious. But whether we choose to call this a "fact" or not depends on how we define the word. If we demand 100% certainty, science can't provide it. If you want certainty, you need to look to mathematics, where knowledge is built through deduction from axioms (a fundamental set of premises), independent of the world.

Science, in contrast, built on evidence and induction, can only ever offer increasing confidence. A key premise of the scientific method is openness to new evidence. If you consider yourself 100% certain, then no new evidence, however convincing, can change your mind. That is not good science.

However, if you accept that science provides evidence for hypotheses, it can offer what we might call indisputable evidence — so robust that disputing it isn't a tenable position. Overturning the not-flat worldview would require such a massive reconsideration of what we understand about reality as to make it practically impossible.

So, "settled science" does not mean we know something with absolute certainty, but that the weight of evidence is heavily in favor of this interpretation. Perhaps more importantly, if someone wants to change the currently held conception, the burden of proof is on them.

All scientific knowledge comes with uncertainty. That is the hallmark of good science. But uncertainty doesn't mean we cannot confidently assert that entropy always increases (the second law of thermodynamics) or that Earth orbits the sun.

Science embraces uncertainty and is open to revision when new information appears, but that does not mean we shouldn't take a position when the evidence stacks up on one side of the balance. Issues that have been rigorously tested can still be considered settled.

Not being 100% certain isn't the same as being 50-50. Admitting doubt isn't the same as both-siding a one-sided issue. The fact that scientists acknowledge uncertainty isn't a reason for championing false balance. But these are the fallacious positions populists are taking when they say "I have no idea" or "I don't side with anybody" on scientific questions.

So when you hear a politician dismissing scientific consensus with phrases like "science is never settled," don't confuse what they are saying with an argument for intellectual humility. They are bluntly attempting to undermine inconvenient truths. Truths which can evolve and grow more nuanced over time, for sure — but whose foundations are strong enough to remain robust in their domain of legitimacy, even as the structure grows around them.

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.

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.

Academic fraud in science is becoming a big problem. For the integrity of our academic institutions and science itself, something must be done to discourage these shady practices.

The term "fraud" in an academic context has different connotations than the everyday use of the word — someone using deception to illegally gain a financial incentive. Scientific fraud sees the perpetrator gain academic acclaim through deceit, dishonesty and false representation.

Fraud in science shows up in several ways, including plagiarism, image manipulation and data fabrication.

But there's also a growing trend of bibliometric manipulation. This includes practices such as self-citation, citation cartels or coercive citation. These practices are problematic because citation is the currency by which academic journal articles — and the authors who write them — demonstrate their standing. The more other researchers cite your article, the more influential it is. When the number of times an author or a journal are referenced is artificially inflated, that can skew what science is perceived to be "important" in the field.

Other forms of author and journal misconduct are also troubling the sector. In fake peer review, authors suggest the names of peers to review their papers but supply contact details that are fake. If journal editors are not careful about checking the details, this essentially allows the submitting authors to write their own reviews. The practice of "gift authorship" sees academics add the names of friends or colleagues as authors to their papers, even though they haven't contributed to the work, allowing them to artificially inflate their publication numbers and citation counts.

There are even entirely ghost-written papers whose named "authors" have had little or nothing to do with the paper at all.

In 2023 the number of papers that made it through "peer review" and were ultimately published but then retracted because they were found to be fraudulent topped 10,000 for the first time. And these papers that were actually discovered to be fraudulent may represent just the tip of the iceberg. Some authors have suggested that as many as one in seven scientific papers are fake although estimates vary.

To some extent academia has brought these problems on itself through the increased reliance on metrics to judge an academic, a journal or an institution's performance. H-indices — a measure of the number of papers an academic has published and how often they have been cited (for example I have an H-index of 28 meaning I have 28 papers which have each been cited at least 28 times) and even cruder metrics like numbers of publications or citation counts are used as proxies for influence.

Hiring and promotion committees often use these benchmarks as shorthand for academic quality, meaning that an academic's job prospects and career progression can depend very strongly on these numbers.

For journals, the impact factor — measuring the average number of citations of each article they publish each year — is a similar metric used to compare quality between publications. Not only does this bring prestige to a journal, but it also attracts better quality submissions forming a positive feedback loop.

The problem with these metrics-cum-performance indicators is that they are gameable by the unscrupulous and the desperate. This is a classic example of Goodhart's law which states: "When a measure becomes a target, it ceases to be a good measure."

These metrics provide perverse incentives for academics to publish as much as possible as quickly as possible, with as many self-citations as they can get away with — sacrificing quality and rigor to the gods of quantity and speed.

Adding in a bunch of references to your own papers (whether relevant or not) and getting a cartel of cooperating colleagues to do the same in their papers is one way of inflating these statistics. It might seem relatively harmless, but stuffing the references section with irrelevant papers makes the paper more difficult to navigate, ultimately degrading the quality of the science presented.

For a recent paper I submitted, one of the referees tasked with checking the paper over before its acceptance for publication requested that I cite a whole bunch of completely irrelevant papers. As a senior academic I felt confident enough to complain to the journal about this referee, but more junior colleagues, for whom that publication might mean the difference between getting the next job or not, might not have felt comfortable complaining. If that journal has integrity, that referee should be scratched from their list, but some journals have fewer scruples than others.

Recent years have seen a move away from the traditional model of academic publishing, where journals make their money by charging end-users to access their articles, and towards an "open-access" model of publishing. On the face of it, open access democratizes research by allowing the public, who are often (if indirectly) the funders of the research through government grants, to access it for free. This is why research funders often provide universities with funding for the "article processing charges" (usually measured in the thousands of dollars) which they then pay to the journals to make the published articles freely available.

But this move towards open access has provided another perverse incentive. The decline of the audience-funded model has meant that the quality of articles is no longer a critical issue for some cynical journals. Even if no-one ever reads them, the money is in the bank and the citation metrics are automatically harvested. The incentive for unscrupulous journals and academics is to publish as many papers as possible as quickly as possible. Inevitably the quality and the reputation of science suffers as a result.

Tackling scientific fraud

So what can be done to reverse the trend of the pervasive and increasing threat of scientific fraud? A two-part report commissioned by the International Mathematical Union (IMU) and the International Council of Industrial and Applied Mathematics (ICIAM) has come up with some suggestions of how we might fight back.

Starting at the top, policy makers, ranging from politicians to funding bodies, should encourage the move away from gameable metrics, including university rankings, journal rankings, impact factors and H-indices. Funding decisions in particular should be decoupled from these numbers.

At an institutional level, research organizations need to discourage the use of bibliometrics in promotion and hiring or else risk low quality scientists who game the system rising above their more diligent colleagues. Institutions can also vote with their feet by deciding which article processing charges to pay, denying the predatory journals their main source of funding.

A big part of the problem is simple lack of awareness amongst scientists and those who work alongside them. Institutions should be doing more to educate their researchers and research administrators about fraudulent academic practices.

Of course, much of the responsibility to reduce academic fraud has to lie with the researchers themselves. This means choosing carefully which editorial board to join, which journals to submit work to and which to undertake peer review for. It also means speaking out when encountering predatory practices, which is easier said than done. Many of those who speak out against predatory practices choose to do so anonymously for fear of reprisals from publishers or even their peers. Consequently, we must also foster a culture in which whistleblowers are protected and supported by their institutions.

Ultimately whether good science is swamped by an ever rising quagmire of poor quality studies or whether we are able to turn back the tide depends on the integrity of researchers and the awareness of the organizations which facilitate and fund it.

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.

When the COVID-19 pandemic broke out, a bizarre conspiracy theory swept through global social media: that the disease was caused by radio-frequency emissions from 5G cell phone towers. The wild theories spread across social media platforms. The belief in this conspiracy was so fervent that the media reported more than 100 incidents of arson and vandalism against 5G (and 4G) infrastructure, as well as numerous instances of abusive or threatening behavior against telecommunications workers.

Why do bizarre events like this happen? In our recent review article, published May 19 in the journal Frontiers in Communication, we showed that conspiracy theories and other widespread incorrect beliefs emerge from complex interactions involving people's cognitive limitations, social influence in groups, and the global-scale spread of ideas across social networks.

This fatal combination of processes at different scales — individual, group and global — has led to the online problems we are seeing today. Their complexity makes the resulting social trends incredibly difficult to combat.

Primed for poor thinking and bizarre group behaviors

The root cause of poor thinking lies in our evolution. Our ability to cope with complex information is limited, so our brains take shortcuts, such as confirmation bias — the tendency to notice things that match our preexisting beliefs and ignore those that don't. For example, we quickly forget waiting in a fast queue but remember how annoying a slow queue is, and ask, "Why am I always in the slow queue?"

Another symptom of our inability to cope with complexity is the tendency to see malicious intent in complex, unexplained events. This tendency has planted the seeds for much injustice, from witch hunts to conspiracy theories. The reality is that unexpected events and behaviors often emerge through networks of interactions, without any conscious prompting.

When people gather in groups, bizarre behaviors often emerge. Like epidemics, false beliefs can spread from person to person. Were you ever afraid to ask a question in class? You think everyone else understands, and you don't want to look stupid, but sometimes, no one understands. Known as pluralistic ignorance, this problem underlies many social problems. For instance, people who are usually helpful often become passive bystanders in the presence of others and fail to help a victim.

Related: Why do people believe in conspiracy theories?

A similar problem is groupthink: Everyone stops voicing their own opinion because they want to protect the reputation of their group, even if they disagree, and blindly follow the leader. Groupthink was implicated in many famous calamities, including the loss of the Space Shuttle Challenger.

Another problem with potentially disastrous consequences is polarization, where a group splits into two camps with mutually opposed, irreconcilable viewpoints that become increasingly separated over time.

Pluralistic ignorance, groupthink and polarization are all known to be "emergent" effects that arise naturally under suitable conditions. This self-organizing behavior of groups is often not understood, and frequently attributed to other causes. It is also why governments, media and public are often caught by surprise when groups suddenly emerge promoting strange agendas.

The above group behaviors emerge spontaneously when individual failures in cognition interact and lead to dysfunctional group behaviours. They are driven by a deep social drive for safety in a group. This fuels errors in the way we think and leads people to take the "safe" route and follow the crowd.

Rapid spread of extremist views

The problem today is that what in the past would have been the whisper of a few voices now has the potential to ignite widespread mayhem. Imagine living in a traditional village, hundreds of years ago. It's a small world. Ideas spread by word of mouth from person to person. They move outward very slowly, when visitors move from village to village. Even today, we still inhabit many kinds of "villages" — family, neighbors, colleagues, friends — and ideas spread as we move between groups.

The advent of mass media has given some people a far wider reach than ever before. It has aided propaganda while also amplifying extreme views. On the internet, groups of people are connected, irrespective of geographical distance, so individual views can be reinforced by large supporting groups.

Communities of like-minded people emerge via social media. This includes the rapid spread of extremist views and conspiracy theories. Connecting individuals with extreme views via social media allows very large groups to share malign views. Bizarre behaviors, like the 5G sabotage mentioned above, can surface, often very quickly.

The truth can't compete with lies

Why do deceptive messages spread well? They can be designed to seduce audiences by exploiting known cognitive biases. This technique is widely used in politically polarized media, social media and biased fact-checking. It exploits confirmation bias and motivated cognition. Truthful messages simply cannot compete with customized fakes.

Another well-known cause is the spreading behavior of social networks, especially when connected by very fast and pervasive digital networks. Studies have found that deceptive messages usually spread in a manner that resembles the models used by epidemiologists in medicine. Social media "influencers" often become "super-spreaders" of false and misleading content.

The above behavior suggests that authorities might suppress the spread of deceptive messages by treating them like epidemics. These are typically defeated by taking three steps: Suppress the source, limit the spread, and increase the immunity of the exposed population. If the pathogen is digital, this suggests blocking or de-platforming creators and spreaders of malign messages, filtering malign content on media platforms, and educating or training audiences to reject malign content.

This is easier said than done.

No way out

Creators and spreaders will leverage freedom of speech legislation, and/or migrate between platforms and media types. Meanwhile, audiences may persist in believing malign nonsense and are prone over time to forget what they are taught. Unfortunately, there is an immense diversity of ways to spread malicious messages.

The world is now confronted with the prospect of a perpetual "arms race" in tactics and technology between purveyors of propaganda and nonsense, and people trying to tell the truth, with audiences that frequently do not know enough to care about the differences between fiction and fact.

Communities that choose not to play in this "arms race" will be inundated with falsehoods and suffer increasing social discord as consensus on any issue of community concern will be disrupted to the point of paralysis. Communities that choose to confront malign actors will have to invest time and resources to play in the "arms race" and attempt to prevent or manage unwanted damage effects.

There is no simple panacea solution: expecting to find one is wishful thinking.

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.

Even if you don't recall many facts from high school biology, you likely remember the cells required for making babies: egg and sperm. Maybe you can picture a swarm of sperm cells battling each other in a race to be the first to penetrate the egg.

For decades, scientific literature described human conception this way, with the cells mirroring the perceived roles of women and men in society. The egg was thought to be passive while the sperm was active.

Over time, scientists realized that sperm are too weak to penetrate the egg and that the union is more mutual, with the two cells working together. It's no coincidence that these findings were made in the same era when new cultural ideas of more egalitarian gender roles were taking hold.

Scientist Ludwik Fleck is credited with first describing science as a cultural practice in the 1930s. Since then, understanding has continued to build that scientific knowledge is always consistent with the cultural norms of its time.

Despite these insights, across political differences, people strive for and continue to demand scientific objectivity: the idea that science should be unbiased, rational and separable from cultural values and beliefs.

When I entered my Ph.D. program in neuroscience in 2001, I felt the same way. But reading a book by biologist Anne Fausto-Sterling called "Sexing the Body" set me down a different path. It systematically debunked the idea of scientific objectivity, showing how cultural ideas about sex, gender and sexuality were inseparable from the scientific findings. By the time I earned my Ph.D., I began to look more holistically at my research, integrating the social, historical and political context.

From the questions scientists begin with, to the beliefs of the people who conduct the research, to choices in research design, to interpretation of the final results, cultural ideas constantly inform "the science." What if an unbiased science is impossible?

Emergence of idea of scientific objectivity

Science grew to be synonymous with objectivity in the Western university system only over the past few hundred years.

In the 15th and 16th centuries, some Europeans gained traction in challenging the religiously ordained royal order. Consolidation of the university system led to shifts from trust in religious leaders interpreting the word of "god," to trust in "man" making one's own rational decisions, to trust in scientists interpreting "nature." The university system became an important site for legitimizing claims through theories and studies.

Previously, people created knowledge about their world, but there were not strict boundaries between what are now called the humanities, such as history, English and philosophy, and the sciences, including biology, chemistry and physics. Over time, as questions arose about how to trust political decisions, people split the disciplines into categories: subjective versus objective. The splitting came with the creation of other binary oppositions, including the closely related emotionality/rationality divide. These categories were not simply seen as opposite, but in a hierarchy with objectivity and rationality as superior.

A closer look shows that these binary systems are arbitrary and self-reinforcing.

Science is a human endeavor

The sciences are fields of study conducted by humans. These people, called scientists, are part of cultural systems just like everyone else. We scientists are part of families and have political viewpoints. We watch the same movies and TV shows and listen to the same music as nonscientists. We read the same newspapers, cheer for the same sports teams and enjoy the same hobbies as others.

All of these obviously "cultural" parts of our lives are going to affect how scientists approach our jobs and what we consider "common sense" that does not get questioned when we do our experiments.

Beyond individual scientists, the kinds of studies that get conducted are based on what questions are deemed relevant or not by dominant societal norms.

For example, in my Ph.D. work in neuroscience, I saw how different assumptions about hierarchy could influence specific experiments and even the entire field. Neuroscience focuses on what is called the central nervous system. The name itself describes a hierarchical model, with one part of the body "in charge" of the rest. Even within the central nervous system, there was a conceptual hierarchy with the brain controlling the spinal cord.

My research looked more at what happened peripherally in muscles, but the predominant model had the brain at the top. The taken-for-granted idea that a system needs a boss mirrors cultural assumptions. But I realized we could have analyzed the system differently and asked different questions. Instead of the brain being at the top, a different model could focus on how the entire system communicates and works together at coordination.

Every experiment also has assumptions baked in — things that are taken for granted, including definitions. Scientific experiments can become self-fulfilling prophecies.

For example, billions of dollars have been spent on trying to delineate sex differences. However, the definition of male and female is almost never stated in these research papers. At the same time, evidence mounts that these binary categories are a modern invention not based on clear physical differences.

Related: Is there really a difference between male and female brains? Emerging science is revealing the answer.

But the categories are tested so many times that eventually some differences are discovered without putting these results into a statistical model together. Oftentimes, so-called negative findings that don't identify a significant difference are not even reported. Sometimes, meta-analyses based on multiple studies that investigated the same question reveal these statistical errors, as in the search for sex-related brain differences. Similar patterns of slippery definitions that end up reinforcing taken-for-granted assumptions happen with race, sexuality and other socially created categories of difference.

Finally, the end results of experiments can be interpreted in many different ways, adding another point where cultural values are injected into the final scientific conclusions.

Settling on science when there's no objectivity

Vaccines. Abortion. Climate change. Sex categories. Science is at the center of most of today's hottest political debates. While there is much disagreement, the desire to separate politics and science seems to be shared. On both sides of the political divide, there are accusations that the other side's scientists cannot be trusted because of political bias.

Consider the recent controversy over the U.S. Centers for Disease Control and Prevention's vaccine advisory panel. Secretary of Health and Human Services Robert F. Kennedy Jr. fired all members of the Advisory Committee on Immunization Practices, saying they were biased, while some Democratic lawmakers argued back that his move put in place those who would be biased in pushing his vaccine-skeptical agenda.

If removing all bias is impossible, then, how do people create knowledge that can be trusted?

The understanding that all knowledge is created through cultural processes does allow for two or more differing truths to coexist. You see this reality in action around many of today's most controversial subjects. However, this does not mean you must believe all truths equally — that's called total cultural relativism. This perspective ignores the need for people to come to decisions together about truth and reality.

Instead, critical scholars offer democratic processes for people to determine which values are important and for what purposes knowledge should be developed. For example, some of my work has focused on expanding a 1970s Dutch model of the science shop, where community groups come to university settings to share their concerns and needs to help determine research agendas. Other researchers have documented other collaborative practices between scientists and marginalized communities or policy changes, including processes for more interdisciplinary or democratic input, or both.

I argue a more accurate view of science is that pure objectivity is impossible. Once you leave the myth of objectivity behind, though, the way forward is not simple. Instead of a belief in an all-knowing science, we are faced with the reality that humans are responsible for what is researched, how it is researched and what conclusions are drawn from such research.

With this knowledge, we have the opportunity to intentionally set societal values that inform scientific investigations. This requires decisions about how people come to agreements about these values. These agreements need not always be universal but instead can be dependent on the context of who and what a given study might affect. While not simple, using these insights, gained over decades of studying science from both within and outside, may force a more honest conversation between political positions.

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

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.

Classroom teaching may be driving a gender gap in math performance, and the effect starts from the moment children begin school, a new study finds.

The study, published July 11 in the journal Nature, included data on the math skills of more than 2.5 million first-grade children in France. It revealed that, while girls and boys started school with a similar level of math skills, within four months, boys performed significantly better than girls. That gap quadrupled in size by the end of the first year of formal education.

Gender gaps in math performance have been documented the world over, and the origin of this disparity has long been blamed on supposedly inherent differences between the genders — "boys are better at math" and "girls are better at language" — that are actually just stereotypes without scientific backing.

But the new study — and previous studies conducted in the U.S. — throw a wrench in those ideas, and instead suggest that something about formal math education spurs the gap to form.

"I was very surprised, not by the fact that there was a gender gap, but that it emerges at the time when formal math instruction in school begins," study coauthor Elizabeth Spelke, a professor of psychology at Harvard University, told Live Science.

Formal education widens gaps

The new study leveraged an initiative by the French Ministry of Education to boost national math standards, which was launched after several years of disappointing performances in international assessments and uncovered the disturbing extent of the math skills gender gap in the country.

Related: Is there really a difference between male and female brains? Emerging science is revealing the answer.

With the aid of cognitive scientists and educators, the French government implemented a universal program of testing for all French children to help teachers better understand the needs of each class and inform updated national standards. Since 2018, every child's math and language skills have been assessed upon entry into first grade, the first mandatory year of schooling in France. They were tested again after four months of formal education and then after one complete year of learning.

These tests revealed no notable differences between girls' and boys' mathematical ability when starting school. However, within four months, a sizable gap opened up between them, placing boys ahead, and that gap only grew as schooling progressed, suggesting that classroom activities had created the disparity, the study authors proposed.

Spelke and her team's analysis covered four national cohorts whose data were collected between 2018 and 2022, and included demographic data to probe the role of external social factors — such as family structure and socioeconomic status (SES) — on school performance. But they found that the emergence of the math gender gap was universal and transcended every parameter investigated: regardless of SES, family structure or type of school, on average, boys performed substantially better in the third assessment than did girls.

This bolstered the hypothesis that an aspect of the schooling itself was to blame. And that idea was further supported by data from the cohort impacted by COVID-related school closures, Spelke added.

"When schools were closed during the pandemic, the gender gap got narrower and then they reopened and it got bigger again," she said. "So there are lots of reasons to think that the gender gap is linked in some way that we don't understand to the onset and progress of formal math instruction."

Causes of the math performance gap

For Jenefer Golding, a pedagogy specialist at University College London who was not involved in the study, the research raises worrying questions about attitudes or behaviors in the classroom that could be creating this disparity.

"Gendered patterns are widespread but they're not inevitable," Golding told Live Science. "It's about equity of opportunity. We need to be quite sure that we're not putting avoidable obstacles in the way of young people who might thrive in these fields." However, separating these educational factors from possible social or biological contributors remains a complex issue, she said.

As a purely observational study, the research does not allow any firm conclusions to be drawn about why this gender gap becomes so pronounced upon starting school. But the alarming findings are already prompting discussion among educational experts.

Educational analyst Sabine Meinck of the International Association for the Evaluation of Educational Achievement drew on her own research, noting that "our data suggest early gendered patterns in parental engagement, [so] gender stereotypes may begin to take root through early childhood play."

For example, "parents report engaging girls significantly more in early literacy activities, while boys are more often involved with building blocks and construction toys," she told Live Science in an email. That may be laying a foundation for how kids engage with reading and math learning in school. These differences in early childhood play have previously correlated with differing levels of scholastic achievement down the line.

The next step requires more research in classrooms, Spelke said, where researchers should gather data to develop interventions that could be useful to students, then test them. "And when we find that something is working, then it can be implemented across the board."

One hundred years after a Tennessee teacher named John Scopes started a legal battle over what the state's schools can teach children, Americans are still divided over evolution.

Scopes was charged with violating Tennessee law by teaching evolution, in a highly publicized July 1925 trial that led to national debate over evolution and education. The trial tested whether a law introduced that year really could punish teachers over evolution lessons. It could and did: Scopes was fined US$100 (£74).

But here's the weird part: while Americans remain deeply divided about whether humans evolved from earlier species, across the Atlantic British people had largely settled this question decades before the Scopes trial.

According to thinktank Pew Research Center data from 2020, only 64% of Americans accept that "humans and other living things have evolved over time". Meanwhile, 73% of Britons are fine with the idea that they share a common ancestor with chimpanzees. That nine-percentage-point gap might not sound like much, but it represents millions of people who think Darwin was peddling fake news.

From 1985 to 2010, Americans were in what researchers call a statistical dead heat between acceptance and rejection of evolution — which is academic speak for people couldn't decide if we were descended from apes or Adam and Eve.

Here's where things get psychologically fascinating. Research into misinformation and cognitive biases suggests that fundamentalism operates on a principle known as motivated reasoning. This means selectively interpreting evidence to reach predetermined conclusions. And a 2018 review of social and computer science research also found that fake news seems to spread because it confirms what people already want to believe.

Related: Evolution: Facts about the processes that shape the diversity of life on Earth

Evolution denial may work the same way. Religious fundamentalism is what researchers call "the strongest predictor" for rejection of evolution. A 2019 study of 900 participants found that belief in fake news headlines was associated with delusionality, dogmatism, religious fundamentalism and reduced analytic thinking.

High personal religiosity, as seen in the US, reinforced by communities of like-minded believers, can create resistance to evolutionary science. This pattern is pronounced among Southern Baptists — the largest Protestant denomination in the US — where 61% believe the Bible is the literal word of God, compared to 31% of Americans overall. The persistence of this conflict is fueled by organized creationist movements that reinforce religious skepticism.

Brain imaging studies show that people with fundamentalist beliefs seem to have reduced activity in the dorsolateral prefrontal cortex — the brain region responsible for cognitive flexibility and analytical thinking. When this area is damaged or less active, people become more prone to accepting claims without sufficient evidence and show increased resistance to changing their beliefs when presented with contradictory information. Studies of brain-injured patients show damage to prefrontal networks that normally help us question information may lead to increased fundamentalist beliefs and reduced skepticism.

Fundamentalist psychology helps explain the US position in international evolution acceptance surveys. In a 2006 study, of over 33,00 people from 34 countries, only Turkey ranked lower than the US, with about 27% accepting evolution compared to America's 40% at the time. Among the developed nations surveyed, the US consistently ranks near the bottom — a pattern that persists in more recent international comparisons.

Research shows that political polarization on evolution has historically been much stronger in the US than in Europe or Japan, where the issue rarely becomes a campaign talking point. In the US, anti-evolution bills are still being introduced in state legislatures.

In the UK, belief in evolution became accepted among respectable clergymen around 1896, according to church historian Owen Chadwick's analysis of Victorian christianity. But why did British religious institutions embrace science while American ones declared war?

The answer lies in different approaches to intellectual challenges. British Anglicanism has a centuries-old tradition of seeking a "via media" — a middle way between extremes — that allowed church leaders to accommodate new ideas without abandoning core beliefs. Historian Peter documented how British religious leaders actively worked to reconcile science and religion, developing theological frameworks that embraced scientific discoveries as revealing God's methods rather than contradicting divine authority.

Anglican bishops and scholars tended to treat evolution as God's method of creation rather than a threat to faith itself. The Church of England's hierarchical structure meant that when educated clergy accepted evolution, the institutional framework often followed suit. A 2024 paper argued that many UK church leaders still view science and religion as complementary rather than conflicting.

A different approach

The British experience proves it's possible to reconcile science and faith. But changing American minds requires understanding that evolution acceptance isn't really about biology — it's about identity, belonging, and the fundamental question of who gets to define truth. People don't reject evolution because they've carefully studied the evidence. They reject it because it threatens their identity. This creates a context where education alone can't overcome deeply held convictions.

Misinformation intervention research suggests that inoculation strategies, such as highlighting the scientific consensus on climate change, work better than debunking individual articles. But evolution education needs to be sensitive. Consensus messaging helps, but only when it doesn't threaten people's core identities. For example, framing evolution as a function of "how" life develops, rather than "why it exists, allows for people to maintain religious belief while accepting the scientific evidence for natural selection.

People's views can change. A review published in 2024, analyzed data which followed the same Gen X people in the US over 33 years. It found that, as they grew up, people developed more acceptance of evolution, though typically because of factors such as education and obtaining university degrees. But people who were taught at a private school seem less likely to become more accepting of evolution as they aged.

As we face new waves of scientific misinformation, the century since the Scopes trial teaches us that evidence alone won't necessarily change people's minds. Understanding the psychology of belief might be our best hope for evolving past our own cognitive limitations.

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

A new artificial intelligence (AI) model can predict and simulate human thought and behavior with a surprising degree of accuracy. The language model, called Centaur, could help researchers improve our understanding of human cognition.

The model was trained on more than 10 million real decisions made by participants of psychological experiments. Using this dataset, Centaur predicted and simulated how people would think and behave with 64% accuracy, researchers reported July 2 in the journal Nature.

Previous AI models could predict some human behavior, but not to this degree. "Centaur is a step beyond in its predictive capabilities," Brenden Lake, who studies psychology and data science at New York University and was not involved in the study, told Live Science in an email.

What is Centaur?

Centaur is an AI model of human cognition that was trained on a curated dataset called Psych-101, which included data from 60,000 people who made more than 10 million individual choices over 160 psychology experiments, according to the paper. The researchers say it might be the world's largest human behavior dataset.

"Essentially, we show the model a full transcript of a psychological experiment from a participant — everything they were told, have seen and have done," study lead author Marcel Binz, a research scientist at the Helmholtz Institute for Human-Centered AI in Germany, told Live Science in an email.

The team then let the model predict what experiment participants chose in specific contexts. If the model predicted a choice that a person didn't make in real life, the researchers would fine-tune the model by correcting its choice. They repeated this process over and over, until Centaur was regularly making correct predictions.

Related: Scientists discover major differences in how humans and AI 'think' — and the implications could be significant

When tested against several established AI models of human thought, Centaur predicted behavior more accurately every time, according to the study. The model is unique because it can anticipate human choices in circumstances that it had never encountered during training, according to a statement from the Helmholtz Association of German Research Centres.

Notably, Centaur can also adapt to changing situations and predict human reaction times.

"We've created a tool that allows us to predict human behavior in any situation described in natural language — like a virtual laboratory," Binz said in the statement.

Studying the brain "at an unprecedented scale"

Binz and his team plan to continue improving the new model. They hope to expand Psych-101 to include demographic and psychological data, including age, socioeconomic status and personality traits, to strengthen its training capabilities. These details would allow Centaur to predict behavior based on an individual's characteristics.

Their next goal is to use Centaur as a proxy for the human brain to determine whether certain patterns they see in the program's data processing correlate with specific decisions. This information could help answer questions about how people process information and how decision-making differs between those with and without mental health conditions, for example, according to the statement.

"Right now, we essentially have a big black box model that predicts human behavior really well," Binz told Live Science. Thanks to Centaur, the researchers can now predict how humans will act, but don't yet have insight into how they arrive at a given decision.

Currently, one big unknown is whether Centaur just predicts human thought or whether it reproduces the underlying cognitive processes, Lake explained. "Is it modeling human mental processes, or just mimicking the outcomes?"

Centaur opens the door to many improvements in psychology and health research. Applications could include predictions of human behavior in clinical contexts or prototyping and analysis of psychology experiments. Scientists could, for example, use the model to figure out how to design an experiment that demonstrates a phenomenon most clearly or requires the fewest participants.

Lake is most excited about the possible educational applications. "Long term, if we can predict how a student learns and reasons through a problem, then we could simulate the effects of different teaching strategies — a potential game changer," he said.

Brain quiz: Test your knowledge of the most complex organ in the body

In this adapted excerpt from "Not Just for the Boys: Why We Need More Women in Science" (Oxford University Press, 2023), physicist Athene Donald examines the role of bias against women in scientific publishing, and its pervasiveness that still persists among academia.

In judging individuals, it might be thought that there are appropriate quantitative and objective metrics to be used. In reality, such metrics can be seen to disadvantage women. Different disciplines and different countries may exhibit these tendencies to a greater or lesser extent. Letters of reference — in science as elsewhere — tend to use fewer stand-out adjectives about women than men, meaning their chance of progression is reduced.

Women's papers are cited less; their grants are on average smaller; and their papers have a harder time getting past reviewers. A recent study of referees' comments highlighted just how unpleasant, not to mention unhelpful, referee comments may be. One example stated: "This paper is, simply, manure." Hardly constructive criticism.

And misogyny can feed into reviewers' comments, sometimes explicitly, as in the case of another review quoted in the same paper: "The first author was a woman. She should be in the kitchen, not writing papers." I would like to think that referee was blacklisted thereafter by the editor concerned, but the fact the editor saw fit to pass the comments on makes me think that was unlikely.

Faced with such responses, many researchers' confidence, and particularly those of women who are in the minority in a field, may be so shaken that they step back or quit altogether.

Underpinning many of the obstacles I've just outlined is bias, unconscious though it may be. Overt discrimination is not only illegal, it is now less evident. Rita Colwell, the bacteriologist and first woman to head up the U.S.'s major funding agency, the National Science Foundation (NSF) was told at the start of her career in 1956 that "we don't waste fellowships on women." This remark made her angry, but it didn't stop her in her professional tracks, as it might have for many women then and since.

Most senior academics would probably be more cautious to express such an opinion outright today, whether or not they privately harbored such thoughts. But it is not necessary to be aware of thinking that women are somehow second-class citizens; that opinion may seep into actions unconsciously.

Bias of this subterranean sort — variously known as unconscious or implicit bias — has come under intense scrutiny in recent years, as it should. Bias, at the individual level, acts as an unconscious reaction to all the stereotypes we have been fed since birth, and comes in many shapes and forms. It can be compared with Nobel Prize-winning Israeli psychologist Daniel Kahneman's two modes of thinking, System I and System 2.

System 1, which operates automatically and quickly, in an essentially involuntary way, would give rise to unconscious bias of the sort that decides a woman is not as capable of being a scientist as a man but would be expected to be very good at childminding or nurturing more generally.

System 2, the slower thinking process, takes the time to think through such a decision. That process allows the bias against women in that first thought to be teased out, confronted and, hopefully, rejected. Organizations that introduce unconscious bias training need to ensure that the need for moving on to slower, more considered (i.e. System 2) thinking is impressed on the individual, not imagine that the training is simply some sort of tickbox exercise telling people they should not be biased.

The latter, too commonly seen in online courses in particular, is totally insufficient to see outcomes shift, the only measure of the success of such a program. It may even backfire.

The subtle ways in which unconscious bias can operate in an academic setting was spelled out at length in Virginia Valian's classic book "Why So Slow?" (MIT Press, 1998) about the progression of women in academia. Despite Valian's book being a quarter of a century old, it is still a sobering read, highlighting all the different places where disadvantage may accrue across the university sector (and not just STEM).

Related: 30 amazing women in science and math

What is the hard evidence, beyond anecdote and suspicion, that unconscious bias impacts on women's careers? Increasing numbers of studies show, in many different guises, just how potent such bias can be.

One of the most striking classes of study is that which compares the reactions of both men and women to identical CVs submitted under a typically male and a typically female name. Valian highlights a study from as far back as 1975 by L.S. Fidell, which demonstrates bias in her own field of psychology. Many studies since have gone on to demonstrate the pervasiveness of such bias, which does not seem to be disappearing.

For instance, in one much-cited study, faculty were sent identical CVs to evaluate, differing only in whether the name at the top appeared to be male or female. These were application materials for an undergraduate science student who had ostensibly applied for a science laboratory manager position. Both male and female faculty were more likely to "hire" the man, as well as offer him more support/training and a higher salary than the woman, despite the identical track records.

The late 1990s saw not only the publication of Valian's book, but also a paper regarding data from the Swedish Medical Research Council concerning biomedical fellowships, which used a Freedom of Information request to obtain the actual evaluation sheets used by the peer-review panel. Sweden, it should be noted, is generally regarded as one of the most egalitarian societies in the world when it comes to gender issues, but the findings would not have led a reader to make that assessment.

The title of the paper presenting the results of this study gives the game away: "Nepotism and Sexism in Peer-Review." Using an array of metrics to devise a figure of merit for impact, it demonstrated graphically how great a difference there was in evaluators' competence scores for men and women objectively assessed to have demonstrated equivalent impact.

The authors' analysis showed that this discrepancy amounted to the equivalent of three papers in a high-ranking journal, such as Nature, or the phenomenal difference of 20 papers in a moderately highly ranked journal. Equally worrying was personal bias, the nepotism of the title, when an applicant was known to a panel member.

Despite that particular person not being allowed to take part in the evaluation itself, as is customary with such funding panels, it transpired that the other panel members scored anyone known to have such an association more highly.

Bias comes in many forms, regardless of how much processes such as excluding a known associate from making the relevant judgement, may attempt to overcome them. When this study appeared, back in 1997, many women already had suspicions that they were being treated unfairly, or at least differentially compared with men.

For far too many of us, the message of the 1988 "Miss Triggs" cartoon will have felt painfully familiar then, and may still do so now. To counter this sort of behavior it is important for those around the table to chip in, to remind everyone that Miss Triggs did just say this and it is good that Mr X agrees.

This technique was brought more forcefully into the public's eyes by female staffers in the Obama White House, who called it amplification. As the Washington Post described it: When a woman made a key point, other women would repeat it, giving credit to its author. This forced the men in the room to recognize the contribution — and denied them the chance to claim the idea as their own.

Every committee around the world, in academia or not, could do with more pushing back on bad behavior from other committee members.

The other tendency seen only too often at committees, debates, and other potentially confrontational situations, is that when men talk over another committee member it is typically a woman. Again, American politics shows a clear example of how to deal with this arrogant behavior; in the 2020 Vice Presidential debate, Kamala Harris calmly said over and over, "Mr Vice President, I'm speaking." Many people would, however, find it easier if someone else, an ally male or female, made that very same point for them.

© Athene Donald. Extract from Not Just for the Boys: Why We Need More Women in Science published by Oxford University Press in May 2023, available in paperback and eBook formats, £16.99.

Do you think you've got decent science knowledge? It's time to put your gray matter to the test with our weekly, free science crossword puzzle.

We've spent hours carefully writing our puzzles to make sure they are challenging but accessible to people of all ages and scientific backgrounds, with answers ranging from unusual animals and ancient rulers, to fundamental theories and Nobel Prize-winning scientists. Don't expect it to be easy, but it will be fun!

All you have to do to play is register once and then you should be logged in for next time, and if you need a hint tap the question mark next to the clue to reveal a letter.

Be sure to share this with your friends, and if you want more fun and games, you can also try out one of our amazing science quizzes on more than 50 different topics.

Note: Our crosswords are currently best experienced on desktop.

Previous science crosswords

Want to try luck with our previous crossword puzzles? The most recent ones can be found below, but you can access the full list of science crosswords here.

—#50: Longest-serving president in US history — 1 across

—#49: 'Short' tempered French emperor — 13 across

—#48: Largest fish on Earth — 6 across

—#47: The 'unicorn of the sea' — 9 across

—#46: Largest desert on Earth — 9 down

Even before kindergarten, Autumn Lloyd feared other kids wouldn't like her because she was twice their size.

In high school, she lost more than half her body weight through a punishing and unsustainable regimen of diet and exercise, which was celebrated by her peers and even featured in a local newspaper.

"Even though I excelled academically, I feel like it never quite mattered as much as this vanity piece," Lloyd told Live Science.

When the weight later returned, as research shows it often does, Lloyd felt scrutinized, which led to her obsessively monitoring her eating and exercise in public, while binge eating in private. A dietician suggested she track her food intake, but it became an obsession, and the pressure to lose weight contributed to self-injury and depression.

By college, she'd been hospitalized twice for suicidal thoughts, with her weight deeply tied to her mental health. She continued a grueling exercise regimen — even running the Chicago marathon twice — before reaching her lowest adult weight. Then the weight returned.

After further weight gain, Lloyd underwent bariatric surgery in 2022, dropping a substantial amount of weight but less than the median. She felt judged by others. "If you appear to be obese, and didn't hit your weight goal, you look [to some] like a failure," she said.

Lloyd's experience of being scrutinized and negatively judged for her weight is not unique. The negative mental health consequences Lloyd faced are also not rare. A growing body of evidence suggests that weight stigma itself leads to poorer mental, physical and economic health for people with higher body weights.

"It really is the norm," Larissa McGarrity, a clinical psychologist at University of Utah Health who studies mental health after weight-loss surgery.

Lloyd's experience of facing weight stigma even after surgery — and that affecting her mental health — is also common.

New research by McGarrity and colleagues suggests that this stigma affects how patients fare after bariatric surgery. Their study, which was published June 5 in the journal Health Psychology, found that shedding weight stigma — rather than the weight itself — may explain why some people report better mental health and less disordered eating after weight-loss surgery.

On the flip side, people who underwent weight-loss surgery but still faced stigma afterward were at higher risk for depression, anxiety and disordered eating compared to their less-stigmatized peers, the study found. These findings suggest that the stigma, not just body size, presents a major barrier to better health for those with obesity.

Related: Childhood obesity should be treated early and aggressively, new guidelines say. Is that safe?

What is weight stigma?

Bias against people who are overweight often stems from the misconception that a person's body weight is entirely within their personal control and can be managed with diet and exercise alone. Research, however, shows that weight is shaped by a complex mix of genetic, physiological, psychological and social factors. Studies show that for most, losing weight and maintaining that weight loss long-term is very difficult without proper medical assistance.

Weight stigma is pervasive, with over 40% of U.S. adults reporting that they've experienced it personally at some point in their lives. Growing evidence shows that weight stigma does not help with weight loss, and what's more, it can worsen health. It's associated with increased stress, inflammation and mental health issues, including depression and disordered eating behaviors, according to the World Obesity Federation.

"There's considerable evidence that societal weight stigma is prevalent and has harmful health consequences for people with obesity," said Rebecca Puhl, deputy director for the Rudd Center for Food Policy and Health at the University of Connecticut, who was not involved in the new study.

However, there's little data about what happens to people after they lose weight through surgery — the most effective intervention for severe obesity and one that's become more common in recent years.

"This new study begins to address this research gap," Puhl told Live Science.

Losing weight doesn't make you "immune"' to stigma

Past research showed that while bariatric surgery improves mental health for most, some people see their mental health worsen afterward. Previous work has also hinted that weight stigma could play a role in the amount of weight lost or regained after surgery.

To understand the effect of weight stigma in this dynamic before and after weight-loss treatment, McGarrity and her colleagues recruited 148 patients who underwent bariatric surgery. They collected data before surgery and 1.5 to three years afterward, measuring patients' experiences of weight stigma in the week prior to survey, alongside measures of their mental health and eating behaviors.

More than 90% of the patients reported experiencing stigma before the procedure, and most — about 60% — experienced significantly less weight stigma post-surgery.

Those who experienced less stigma afterward saw notable improvements in mental and physical health. They were more likely to have a lower weight at that time point compared to patients who continued experiencing stigma post-surgery. However, weight loss itself was not associated with the improvement in mental health.

Related: Weight-loss surgery is becoming more common among US teens

About 40% of participants reported regularly experiencing weight stigma following their procedures, and these people were at increased risk for mental health problems compared to their peers. The higher the level of weight stigma reported post-operatively, the higher the risk for poor mental health, eating behavior and weight outcomes. Again, these effects appeared to be tied to the perception of stigma rather than to any weight loss they had after the surgery.

The study suggests "bariatric surgery patients are not immune to the effects of weight stigma, even years after surgery, even after significant amounts of weight loss," McGarrity said.

She emphasized that the study design has important limitations: the patients' experience of weight stigma was self-reported, and for obvious ethical reasons, the study didn't assign people to face differing levels of weight stigma. As such, it cannot directly establish cause and effect. Moreover, the patients were drawn from only one region and their perceived stigma was only measured at one time point after surgery.

Puhl added that it would also have been helpful to get a more detailed picture of the patient's experience over time. And more research is needed to understand how much this bias affected patient health.

The takeaways

The findings highlight how important it is to address weight stigma at every stage of a patient's weight journey, and not assume it will resolve after surgery, Puhl said.

McGarrity said public health and policy officials, as well as members of the media, should examine whether the public conversation around weight could be harming people's health. On an individual level, she said that everyone can "do better with the people in our lives who struggle with weight — to not just be one more person that conveys the [message of] 'just eat less and exercise more.'"

That jives with Lloyd's experience. "If you're in a world where weight stigma is hitting you from every side, I think that will directly hinder your progress," Lloyd said.

Lloyd says she's learned to tackle the aspect of weight stigma she can control: her own perception of her weight. To people who live with a higher weight, she says to be kind to themselves.

"The journey is very difficult. There's a lot of noise to filter through, and there's some fights that we just don't have the bandwidth to get into," Lloyd said. "You're not broken. You're not failing because you haven't reduced your weight."

Editor's note: This story was updated on June 11, 2025, to adjust Autumn Huett's name to Llyod, her married name. The article was first published June 10.

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

"Can machines think?" That's the core question legendary mathematician and computer scientist Alan Turing posed in October, 1950. Turing wanted to assess whether machines could imitate or exhibit human-level intelligent behavior, and so he came up with a test called the "imitation game." This later became known as the Turing test, which is commonly used to assess how well a machine can mimic human behavior.

The genesis of Turing's test came from the inherent difficulty in establishing objective criteria that distinguishes original thought from the imitation of it. The challenge is that evidence of original thought could be denied with the argument that a machine was simply programmed to seem intelligent. Essentially, the crux of proving if machines can think is defining what thinking is.

Related: 8 of the weirdest robots in the world right now

Turing wanted to challenge the idea that the mechanical nature of computers means they cannot, in principle, think. The mathematician was positing that, if a computer appears indistinguishable from a human, then why should it not be considered a thinking entity?

How does the Turing test work?

Turing proposed a three-party game. He first outlined a test in which a man and woman go into separate rooms and party guests use typewritten answers to try and determine which person is which, while the man and woman try to convince them that they are the opposite sex.

From there, Turing proposed a test whereby a remote interrogator is tasked with asking questions to a computer and human subject, both unseen, for five minutes in order to determine which is sentient. A computer's success at "thinking" could then be measured by how likely it is to be misidentified as a human.

A later iteration of the imitation game, proposed by Turing in 1952 in a BBC broadcast, would see a computer try and convince a jury of people that it was human.

The Turing test was created as more of a philosophical thought experiment than a practical means of defining machine intelligence. However, it grew to be seen as an ultimate target for machine learning and artificial intelligence (AI) systems to pass in order to demonstrate artificial general intelligence.

Turing predicted that by the early 2000s, a programmed computer would be able to “play the imitation game so well that an average interrogator will not have more than 70 per cent chance of making the right identification after five minutes of questioning.”

But, that did not come to pass. However, the rise of ChatGPT and other artificial intelligence systems and large language models (LLM) has reignited the conversation around the Turing test.

In June 2024, researchers claimed that the LLM GPT-4 was judged to be human 54% of the time in the Turing test within five minutes of questioning. That resoundingly beats Turing’s prediction of 30%, despite being two decades on from the mathematician's predicted date. But this research from the University of San Diego only involved two players in the test rather than Turing’s original three-player game, so GPT-4 didn’t pass the Turing test in the specific conditions he defined.

Nevertheless, this research still shows how such AIs can at least imitate humans with some success.

Challenges and limitations of the Turing test

While passing the Turing test might be the big goal to prove thinking in AI systems, the test has its limitations and opponents.

Turing himself detailed and addressed nine objections to his test and theory in proving machines could think; these range from the theological concept of thought and the idea that machines can't feel emotions, or have a sense of humor, to logical mathematical limitation that will simply prevent a machine from answering a question or getting it correct.

But perhaps the most relevant objection comes from mathematician Ada Lovelace, who when commenting on computing pioneer Charles Babbage’s Analytical Engine, suggested that a machine cannot "originate anything" and can only do whatever we order it to perform. Turing's retort in his paper was to ask whether humans can indeed ever do anything really new in a deterministic world bound by the laws of nature and the boundaries of the universe. Turing also noted that computers may be constrained but could still potentially do unexpected things — in the same way that humans can despite being constrained by our genetic makeup and biology.

Beyond this is the fact that the Turing test does not, per se, indicate consciousness or intelligence; rather it works to critique what is understood as thought and what could constitute thinking machines. The test is also reliant on the judgement of the interrogator, a comparison to humans and the judgment of behaviors only.

Then there's the argument that the Turing test is designed around how a subject acts, meaning a machine can merely simulate human consciousness or thought rather than actively having its own equivalent. This can lead to the Turing trap — in which AI systems are excessively focused on imitating humans rather than being designed to have functions that allow humans to do more or boost their cognition beyond the possibilities of the human mind.

Is the Turing test still relevant?

While the Turing test might be held as a benchmark for AI systems to surpass, Eleanor Watson, an expert in AI ethics and member of the Institute of Electrical and Electronics Engineers (IEEE),told Live Science that "The Turing Test is becoming increasingly obsolete as a meaningful benchmark for artificial intelligence (AI) capability."

Watson explained that LLMs are evolving from simply mimicking humans to being agentic systems that are able to autonomously pursue goals via programming "scaffolding" — similar to how human brains build new functions as information flows through layers of neurons.

"These systems can engage in complex reasoning, generate content creation and assist in scientific discovery. However, the real challenge isn't whether AI can fool humans in conversation, but whether it can develop genuine common sense, reasoning and goal alignment that matches human values and intentions," Watson said. "Without this deeper alignment, passing the Turing Test becomes merely a sophisticated form of mimicry rather than true intelligence."

Essentially, the Turing test may be assessing the wrong things for modern AI systems.

As such, scientists "need to develop new frameworks for evaluating AI that goes beyond simple human imitation in order to assess capabilities, limitations, potential risks, and most importantly, alignment with human values and goals," Watson said.

Unlike the Turing test, these frameworks will need to account for the strengths of AI systems and their fundamental differences from human intelligence, with the goal of ensuring AIs "enhance, rather than diminish, human agency and wellbeing," Watson added.

"The true measure of AI will not be how well it can act human,” Watson concludes, “but how well it can complement and augment humanity, lifting us to greater heights."

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.

People can read intention in each other's gazes, recent research finds, lending evidence to this well-known assumption about human communication.

The study reveals how humans use their eyes to communicate nonverbally. In the future, this line of research could lead to a better understanding of how people with conditions that affect social skills, such as autism, process these subtle, nonverbal cues.

You don't have to be a psychologist to know that the eyes convey a lot of information; there's a reason for the phrase "the eyes are the window to the soul." But researchers have long been digging into exactly how the brain picks up tiny eye movements and translates them into an understanding of another person's thoughts, feelings or mental state. How can we discern when a look is imbued with meaning and when it's just a casual, meaningless glance?

"We try to find the reason for why our brain engages with social information differently," said Jelena Ristic, a professor of psychology at McGill University in Canada and the senior author of the study, which was published online in September in the journal Communications Psychology.

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

In the research, Ristic and her colleagues were interested in understanding whether people respond to intentional eye movements differently than they do to unintentional eye movements. First, they recorded people sitting in front of a screen and moving their eyes in response to prompts on that screen. For instance, the individuals were sometimes prompted to move their eyes left or right — their choice — and other times, they were expressly directed to look one way or the other.

"The only difference between those conditions is that, in one case, people are making intentional eye movements, and in another case, they're making instructed or non-intentional eye movements," Ristic told Live Science.

Next, the researchers recruited about 80 participants to watch these recordings, which were clipped just before the people in the video actually moved their eyes. In each clip, the participants were asked to predict which way each person would glance: left or right.

"They were faster to make these decisions when the looks were intentional," Ristic said. This difference in prediction speed was a matter of a few milliseconds, but it revealed that people process intentional and unintentional gazes differently.

In two follow-up experiments, each with another set of about 70 participants, the researchers tested whether this difference in processing speed changed how people followed the gaze of the person on the screen. Perhaps they'd be faster to track the intentional gazes, for instance. But unexpectedly, the intention did not make a difference, Ristic said.

That suggests that separate processes in the brain might be detecting the intentionality of a person's glance and then formulating a response. Or perhaps, that information about intentionality is gathered later in the social interaction, after the viewer has adequately observed the other person's gaze.

The researchers analyzed their video recordings to figure out what participants might be seeing that would help them more quickly predict eye motion before a person intentionally shifted their gaze. To the naked eye, Ristic said, it didn't look like the recorded individuals were moving at all. But in a close analysis, the researchers found that there was more motion around the eye area before someone chose to move their gaze versus when they were told which way to look. These tiny movements might have been a "tell."

"We speculate based on this that these very subtle motion signals are communicated very quickly to indicate intentionally to others and that our system [as the observer] is very sensitive to that," Ristic said.

The next step in the research, she said, will be to use more precise eye-tracking techniques to understand these subtle signals. The researchers will also film new videos in which they ask participants to move their eyes with a particular intention — to help someone or to deceive them, for example — to see if viewers can pick up on the specific intent behind someone's gaze.

Finally, the team plans to conduct follow-up studies with participants who have a condition that affects social skills, such as autism spectrum disorder or attention-deficit/hyperactivity disorder (ADHD). In these neurodevelopmental disorders, people may struggle to notice and interpret social cues. The researchers are interested in investigating the specific point in processing where these individuals differ from neurotypical people.

"This is one of the holy grail questions in the autism world," Ristic said. "Where is the system working differently, and in which aspects?"

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.

Seeing or hearing someone yawn can make you yawn. This phenomenon is not limited to humans; some animals experience contagious yawning, too.

But why is yawning contagious?

Brain cells called mirror neurons may play a role in contagious yawning, Dr. Charles Sweet, a board-certified psychiatrist and medical adviser at Linear Health, told Live Science in an email. Mirror neurons respond to actions that we observe in others.

"When you see someone yawn, those neurons fire up," Sweet said. This neurological mechanism may explain why yawning spreads so easily within social groups.

Research has also shown that people and animals are more likely to yawn in response to yawns from familiar individuals compared with acquaintances and strangers. For example, in a 2013 study, dogs yawned more frequently when watching their owner yawn than when watching a stranger yawn. This pattern, known as the "familiarity bias," is likely driven by attentional biases, said Andrew Gallup, a teaching professor of behavioral biology at Johns Hopkins University, as individuals naturally pay closer attention to those within their social circles.

Related: Is it possible to avoid unwanted thoughts?

One hypothesis is that contagious yawning evolved to boost threat detection within groups, Gallup told Live Science in an email.

In a 2007 study published in the journal Evolutionary Psychology, Gallup and colleagues found that yawning helps cool the brain. This cooling effect may improve alertness and mental processing efficiency in the yawner, Gallup hypothesized. If yawning spreads through a group, it could help enhance the group's threat awareness, the team proposed.

More recent research by Gallup in humans has shown that simply seeing others yawn can improve an individual's ability to detect threats, further supporting the idea that contagious yawning increases vigilance levels in a group.

Another hypothesis is that contagious yawning evolved to keep groups in sync. Yawns follow a natural circadian rhythm and often signal transitions between activities. So, when yawning spreads within a group, it may serve to align activity patterns and behavior, Gallup explained.

Support for this hypothesis comes from a recent study on wild African lions (Panthera leo). The researchers observed yawns from 19 lions in two social groups and tracked the connection between yawn contagion and motor synchrony — when individuals show the same changes in behavior. The results were striking: Lions that "caught" a yawn from another lion were 11 times more likely to mirror the movements of the lion that yawned first, compared with lions who hadn't caught the yawn.

Not everyone is equally susceptible to contagious yawning. In controlled studies, approximately 40% to 60% of typical volunteers yawned in response to watching another person yawn in a video.

A key question in research is whether contagious yawning is linked to empathy. There have been several studies, but findings have been mixed. "Some studies have found predicted connections, while others fail to demonstrate such a relationship," Gallup said.

Although early research suggested that children with autism were less likely to yawn contagiously than nonautistic children were, a follow-up study found that when participants were explicitly instructed to focus on the yawning stimulus, this difference disappeared, Gallup explained, underlining that attention also plays a key role in yawn contagion.

One of the most consistent discoveries is the negative association between contagious yawning and psychopathy. "Individuals who score higher on measures of psychopathic traits tend to be less susceptible to contagious yawning," Gallup said. (Psychopathic traits include selfishness, manipulation and callousness.)

"At the end of the day, contagious yawning is less about being tired and more about connection," Sweet said. "It's your brain's quiet way of syncing up with the people (and sometimes pets) around you."

In the recent flurry of executive orders from President Donald Trump, one warned of "a distorted narrative" about race "driven by ideology rather than truth." It singled out a current exhibition at the Smithsonian American Art Museum titled "The Shape of Power: Stories of Race and American Sculpture" as an example. The exhibit displays over two centuries of sculptures that show how art has produced and reproduced racial attitudes and ideologies.

The executive order condemns the exhibition because it "promotes the view that race is not a biological reality but a social construct, stating 'Race is a human invention.'"

The executive order apparently objects to sentiments such as this: "Although a person's genetics influences their phenotypic characteristics, and self-identified race might be influenced by physical appearance, race itself is a social construct." But those words are not from the Smithsonian; they are from the American Society of Human Genetics.

Scientists reject the idea that race is biologically real. The claim that race is a "biological reality" cuts against modern scientific knowledge.

I'm a historian who specializes in the scientific study of race. The executive order places "social construct" in opposition to "biological reality." The history of both concepts reveals how modern science landed at the idea that race was invented by people, not nature.

Related: What's the difference between race and ethnicity?

Race exists, but what is it?

At the turn of the 20th century, scientists believed humans could be divided into distinct races based on physical features. According to this idea, a scientist could identify physical differences in groups of people, and if those differences were passed on to succeeding generations, the scientist had correctly identified a racial "type."

The results of this "typological" method were chaotic. A frustrated Charles Darwin in 1871 listed 13 scientists who identified anywhere between two and 63 races, a confusion that persisted for the next six decades. There were almost as many racial classifications as racial classifiers because no two scientists could seem to agree on what physical characteristics were best to measure, or how to measure them.

One intractable problem with racial classifications was that the differences in human physical traits were tiny, so scientists struggled to use them to differentiate between groups. The pioneering African American scholar W.E.B. Du Bois noted in 1906, "It is impossible to draw a color line between black and other races … in all physical characteristics the Negro race cannot be set off by itself."

But scientists tried. In an 1899 anthropological study, William Ripley classified people using head shape, hair type, pigmentation and stature. In 1926, Harvard anthropologist Earnest Hooton, the leading racial typologist in the world, listed 24 anatomical traits, such as "the presence or absence of a postglenoid tubercle and a pharyngeal fossa or tubercle" and "the degree of bowing of the radius and ulna" while admitting "this list is not, of course, exhaustive."

All this confusion was the opposite of how science should operate: As the tools improved and as measurements became more precise, the object of study − race − became more and more muddled.

When sculptor Malvina Hoffman's "Races of Mankind" exhibit opened at Chicago's Field Museum in 1933, it characterized race as a biological reality, despite its elusive definition. World-renowned anthropologist Sir Arthur Keith wrote the introduction to the exhibition's catalog.

Keith dismissed science as the surest method to distinguish race; one knows a person's race because "a single glance, picks out the racial features more certainly than could a band of trained anthropologists." Keith's view perfectly captured the view that race must be real, for he saw it all around him, even though science could never establish that reality.

In the scientific study of race, however, things were about to change.

Turning to culture to explain difference

By 1933, the rise of Nazism had added urgency to the scientific study of race. As anthropologist Sherwood Washburn wrote in 1944, "If we are to discuss racial matters with the Nazis, we had better be right."

In the late 1930s and early 1940s, two new scientific ideas came to fruition. First, scientists began looking to culture rather than biology as the driver of differences among groups of people. Second, the rise of population genetics challenged the biological reality of race.

In 1943, anthropologists Ruth Benedict and Gene Weltfish wrote a short work also titled The Races of Mankind. Writing for a popular audience, they argued that people are far more alike than different, and our differences owe to culture and learning, not biology. An animated cartoon short later gave these ideas wider circulation.

Benedict and Weltfish argued that while people did, indeed, differ physically, those differences were meaningless in that all races could learn and all were capable. "Progress in civilization is not the monopoly of one race or subrace," they wrote. "Negroes made iron tools and wove fine cloth for their clothing when fair-skinned Europeans wore skins and knew nothing of iron." The cultural explanation for different human lifestyles was more robust than confused appeals to an elusive biological race.

The turn to culture was consistent with a deep change in biological knowledge.

A tool to understand evolution

Theodosius Dobzhansky was a preeminent biologist of the 20th century. He and other biologists were interested in evolutionary changes. Races, which supposedly didn't change over time, were therefore useless for understanding how organisms evolved.

A new tool, what scientists called a "genetic population," was much more valuable. The geneticist, Dobzhansky held, identified a population based on the genes it shared in order to study change in organisms. Over time natural selection would shape how the population evolved. But if that population didn't shed light on natural selection, the geneticist must abandon it and work with a new population based on a different set of shared genes. The important point is that, whatever population the geneticist chose, it was changing over time. No population was a fixed and stable entity, as human races were supposed to be.

Sherwood Washburn, who happened to be Dobzhansky's close friend, brought those ideas into anthropology. He recognized that the point of genetics was not classifying people into fixed groups. The point was to understand the process of human evolution. This change reversed everything taught by Hooton, his old teacher.

Writing in 1951, Washburn argued, "There is no way to justify the division of a … population into a series of racial types" because doing so would be pointless. Presuming any group to be unchanging stood in the way of understanding evolutionary changes. A genetic population was not "real"; it was an invention of the scientist using it as a lens to understand organic change.

A good way to understand this profound difference relates to roller coasters.

Anyone who's been to an amusement park has seen signs that precisely define who is tall enough to ride a given roller coaster. But no one would say they define a "real" category of "tall" or "short" people, as another roller coaster might have a different height requirement. The signs define who is tall enough only for riding this particular roller coaster, and that's all. It's a tool for keeping people safe, not a category defining who is "really" tall.

Similarly, geneticists use genetic populations as "an important tool for inferring the evolutionary history of modern humans" or because they have "fundamental implications for understanding the genetic basis of diseases."

Anyone trying to pound a nail with a screwdriver soon realizes that tools are good for tasks they were designed for and useless for anything else. Genetic populations are tools for specific biological uses, not for classifying people into "real" groups by race.

Whoever wanted to classify people, Washburn argued, must give the "important reasons for subdividing our whole species."

The Smithsonian's exhibit shows how racialized sculpture was "both a tool of oppression and domination and one of liberation and empowerment." Science agrees with its claim that race is a human invention and not a biological reality.

The Conversation U.S. receives funding from the Smithsonian Institution.

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

Since the inauguration of President Donald Trump on Jan. 20, a number of actions aimed at slashing federal science spending and restricting research topics have begun to worry the American scientific community.

These include firing many — then rehiring some — staff across major science agencies, as well as holding up over a billion dollars in federal funding and triggering a pause in graduate admissions and faculty job postings at universities. Executive orders prompted the flagging of research projects for review based on whether they contain words like "female" or "gender," and scrubbing peer-reviewed papers from agency websites if they conflict with the current administration's policy priorities.

In response, scientists have begun to mobilize. On her Bluesky feed, Colette Delawalla, a graduate student in clinical psychology at Emory University in Atlanta, posted on Feb. 9 simply, "Get in Dorks, we are going protesting."

Delawalla is the lead organizer of Stand Up for Science, a grassroots movement with three main policy goals: to end political interference in science, to secure science funding, and to defend diversity, equity, inclusion and accessibility in science.

Related: Trump executive order calls mental health prescriptions a 'threat' — why?

On Friday (March 7), people in more than two dozen cities across the U.S. attended Stand Up for Science rallies. The main rally was held in D.C., with speakers like Bill Nye slated to talk, and 31 other cities held their own events.

Live Science reported from two of these locations — New York City and Raleigh, North Carolina — to learn more about what science supporters want from the U.S. government.

In New York City

Hundreds of rally attendees assembled in Washington Square Park in Manhattan under a bright-blue sky, although they occasionally had to grasp their signs tightly as they were buffeted by gusts of strong wind.

The crowd represented a wide range of age groups and vocations. Young children teetered on their caregivers' shoulders, high schoolers hoisted homemade cardboard signs, members of professional groups crowded together for a group photo in front of the square's iconic arch, and prominent professors stood alongside members of state government.

Among the clever and emphatic signage was the giant head of the beloved Muppets character Beaker, worn by an attendee affiliated with the Zuckerman Institute at Columbia University.

Although many attendees were scientists, not all were.

"I think all expertise is under attack. That's really why I'm here," said Randi from Brooklyn, a retiree who previously worked in construction and asked that her last name not be used. "When you undermine expertise, then nobody knows what the facts are." She said she "had to come out" to the event after she heard that the Centers for Disease Control and Prevention was telling scientists to scrub their research papers of "words that might cause trouble."

"I think they're going after experts of all kinds, trying to bankrupt them so that eventually functions that scientists do will all be privatized," Randi told Live Science.

Two young attendees, Caitlin and Amalia, who declined to give their last names, held up signs reading, "Science is for everyone" and "Girls just wanna have fun-ding for research." In regard to the recent developments in the federal government, Amalia, a high-school senior who plans to major in biology in college, said, "I'm just kind of in awe — shock — that this is all going on."

Among the medical providers in attendance was Dr. Michelle Ng Gong, secretary of the American Thoracic Society (ATS), a medical society dedicated to accelerating the advancement of global respiratory health. The work of ATS is aimed at preserving lung health, in terms of both caring for patients and understanding factors that affect lung health, such as climate change and pollution, Gong said.

Cutting National Institutes of Health (NIH) funding for diverse research teams and studies that aim to meet the needs of all patients is "basically gambling on our futures," she emphasized.

"Scientists have always tried to speak through our work, and our publications," she added. "But now I think we need to do a better job of communicating overall the impact that science has on day-to-day life."

That point was driven home by the chant "Science, not silence," which the crowd called out between the speakers featured at the rally. When asked to raise their hands if their work relies on federal research funding, the majority of the crowd reached to the sky.

Among the formal speakers at the rally was Dr. Claire Pomeroy, president and CEO of the Lasker Foundation, which gives out the coveted Lasker Awards for biomedical research. She spoke of her experience during the HIV/AIDS epidemic, when she couldn't offer patients solutions; she could only hold their hands and attend their funerals. Science changed that — now, people with HIV can lead long, prosperous lives, and the infection can be prevented with powerful medications.

Attacks on science put those kinds of breakthroughs in jeopardy, Pomeroy emphasized. She encouraged those gathered to stay informed and keep their networks outside science in the loop, as well. "We have to spread the message beyond this crowd," Pomeroy said.

Josh Dubnau, a Stony Brook University professor who studies ALS and other neurodegenerative disorders, underscored the wide range of jobs that NIH funding supports — tens of thousands of jobs in New York State, alone, he said. He called the funding cuts and firings orchestrated by the Department of Government Efficiency (DOGE) and other federal actors a "planned and coordinated assault" on science, as well as on America's education system.

Dubnau urged the rally attendees to band together in response, not stay silent in an attempt at self preservation.

Additional speakers included Griffin Gowdy, a biomedical researcher with Scientists Rebellion, a collective calling for action to address the climate crisis, who encouraged attendees to start or join organizations assembling on behalf of the scientific enterprise.

"Like a burning Tesla battery that not even Poiseden himself could put out, we will never stop fighting for what's right," Gowdy quipped.

Several New York politicians also stepped to the microphone, including state Assemblymember Harvey Epstein and state Sen. Brad Hoylman-Sigal.

Epstein, who also teaches an environmental law clinic at CUNY Law School, acknowledged there will be cuts to federal funding but called on the crowd to collectively stand up to "bullies in the White House" despite that.

Hoylman-Sigal condemned Department of Health and Human Services Secretary Robert F. Kennedy Jr. for claiming measles can be cured with vitamin A and fish oil amid the ongoing outbreak in Texas and said it's "not right" that anyone is dying from vaccine-preventable diseases.

To conclude his talk, Hoylman-Sigal also thanked scientists for their role in making it so that HIV is no longer a death sentence; as a gay man, Hoylman-Sigal was grateful for the lives HIV drugs have spared within the LGBTQ+ community.

In Raleigh

A crowd of around 500 people gathered slowly but steadily on Halifax Mall, a block from the state capitol building and the North Carolina Museum of Natural Sciences. A stiff wind blew posters willy-nilly as people listened to speakers, including Jamie Vernon, the executive director of Sigma Xi, the scientific honor society headquartered in North Carolina's "Research Triangle."

Protest leaders encouraged the gathering of young, mid-career and retired scientists and supporters to take occasional "warm-up breaks" while chanting phrases like "What do we want? Science! When do we want it? Now!" and "Vaccines are awesome, imagine if we lost 'em."

Toxicologist Noelle Muzzy told Live Science that she organized the Raleigh Stand Up for Science rally because "in one sentence: science is under attack."

The executive orders affecting funding, federal jobs and censorship were at the forefront for Muzzy. "All of that is limiting what we can do as researchers. That's very concerning, not just for career scientists but also for the general public," she said, adding that "we're going to be losing access to new technology that could save lives and produce medical treatments as well."

But the general tenor of the Raleigh event was optimistic, even as many signs satirized the language that President Trump and Elon Musk in particular have used recently to denigrate science they deem worthless, such as "Transgender ≠ Transgenic."

"I'm here because I support science in every way, shape and form. Not only for myself and my colleagues personally, but for everyone because science is, in fact, for everyone," McKenzie Gehris, a graduate student in pharmacology at the University of North Carolina at Chapel Hill, told Live Science. She had a poster of the muppet Beaker that read, "This is the only orange muppet I trust to tell me about science."

"The research that scientists do across the country helps cure diseases, helps figure out things about our climate and the world that we live in," Gehris said. "It's important that we fund that sort of research."

Plenty of people get the heebie-jeebies when they stand near the edge of a high cliff, and many would prefer not to pet a tarantula or cradle a boa constrictor. But for some people, their fears surrounding a particular situation grow to be out of proportion with the actual danger it poses.

In that case, these individuals may be diagnosed with a specific phobia. Specific phobia refers to an extreme fear or anxiety about a certain object or situation. Colloquially, people sometimes say they have a phobia of something they're fearful or wary of — but what really counts as a specific phobia, as it's understood in psychology?

To qualify as a specific phobia, a fear must be persistent — it happens each time the object or situation is encountered — and it must interfere with a person's daily life, affecting their hobbies, relationships or work, for instance.

"You have to cross the line of what’s called 'distress' or 'impairment,'" said Ellen Hendriksen, a clinical psychologist at Boston University's Center for Anxiety and Related Disorders. "Distress, meaning it freaks you out, and impairment, meaning it keeps you from living the life you want to live," Hendriksen told Live Science.

Related: 'This is largely uncharted territory': Scientists reveal the brain's 'fear circuit' works differently than we thought

According to Martin Antony, a clinical psychologist at Toronto Metropolitan University who leads an anxiety research and treatment laboratory, psychologists break specific phobias into these five categories:

• Animals: All animals fall under this category. Snakes and spiders are common triggers, with studies in different countries finding that spider phobias affect between 2.7% and 9.5% of the population.
• Natural environment: A fear of heights, a fear of water, and a fear of storms are some examples of phobias triggered by features of nature.
• Blood, injury, injection: These phobias involve the fear of needles, surgery, blood or similar stimuli.
• Situational: Situational phobias involve a fear of being in a certain situation or environment. Driving, flying and being in elevators are common examples of these phobias.
• Other: This category covers anything that doesn't fall into the other four categories, such as a fear of clowns or of costumed figures. "People can be afraid of anything," Antony said.

Sometimes, specific phobias develop after a person experiences a traumatic event, or after they have a panic attack that then gets associated with the environment and leads to a self-reinforcing fear of that scenario, said Sandra Capaldi, a clinical psychologist at the University of Pennsylvania Perelman School of Medicine. For example, someone who has a panic attack while they happen to be driving might develop a phobia of getting behind the wheel again for fear that they might have another attack and wreck the car.

However, sometimes phobias develop without any particular trigger. In many cases, these are phobias that center around something that's actually dangerous — like falling from a height — but a person's fear is out of proportion with the actual risk.

"This anxiety that's associated with the fear is overestimating both the likelihood that they're going to encounter some sort of featured object of the situation, or [overestimating] the intensity and the severity of the consequence," Capaldi said.

People with one anxiety disorder are more likely to have another anxiety disorder, Antony said, so specific phobias sometimes co-occur with generalized anxiety or panic disorders. On occasion, these disorders can overlap in a way that makes them tricky to diagnose.

Antony once treated a woman with social anxiety who also feared driving. He eventually realized that her fear of driving wasn't a specific phobia, though. She didn't fear crashing, he said, but rather that other drivers would judge her on the road. In her case, the driving fear was an offshoot of her social anxiety, rather than a specific phobia.

"The diagnosis isn't always clear-cut, and you can't always go by the situation people fear," Antony said. "You also have to look at why they fear that situation."

Fortunately, phobias have a well-researched and very effective treatment. The gold standard is exposure therapy, in which the patient gradually faces their fear in a controlled manner and environment. A person who has a phobia of snakes might first look at a squiggly line on a piece of paper, then a cartoon drawing of a snake, then a photo of a snake and, finally, the real thing.

"We want to push the client out of their comfort zone, but not into a panic zone," Hendriksen said. "The zone in between that is what I call the 'learning zone.' We do something a little bit hard, and it does activate our anxiety. But then when the feared outcome doesn't happen, our fear doesn't get reinforced."

The patient is in control of this process, Hendriksen added. They're never surprised by any stimuli and can decide how they want to proceed. Patients may start the treatment in a therapist's office and gradually move to the real world. Someone with a phobia of elevators might start by looking at pictures or videos of elevators, then eventually step on a real elevator themselves, for example.

Psychologists help the person monitor their anxiety throughout the process, aiming to keep the patient in a place of discomfort but not panic. As the person experiences the anxiety without any actual danger from the phobia trigger, the brain's fear system becomes desensitized and the anxiety gradually decreases.

In some special cases, psychologists might recommend an additional therapy alongside exposure therapy. This is most often true in the case of blood, injury or injection fears, Antony said.

About 70% of people with a blood phobia and half of those with a needle phobia report a fear of fainting, which is caused by an involuntary reflex called the vasovagal response. Being prone to fainting, at baseline, probably reinforces the phobia in these people; in other words, their fear of the situation is validated when they really do faint. So, in these cases, a patient might also practice a strategy called "applied muscle tension." This involves tightening certain muscles to reduce the vasovagal response, which helps prevent fainting.

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

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.

Over the past decade, furtive commercial entities around the world have industrialized the production, sale and dissemination of bogus scholarly research. These paper mills are profiting by undermining the literature that everyone from doctors to engineers rely on to make decisions about human lives.

It is exceedingly difficult to get a handle on exactly how big the problem is. About 55,000 scholarly papers have been retracted to date, for a variety of reasons, but scientists and companies who screen the scientific literature for telltale signs of fraud estimate that there are many more fake papers circulating — possibly as many as several hundred thousand. This fake research can confound legitimate researchers who must wade through dense equations, evidence, images and methodologies, only to find that they were made up.

Even when bogus papers are spotted — usually by amateur sleuths on their own time — academic journals are often slow to retract the papers, allowing the articles to taint what many consider sacrosanct: the vast global library of scholarly work that introduces new ideas, reviews and other research and discusses findings.

These fake papers are slowing research that has helped millions of people with lifesaving medicine and therapies, from cancer to COVID-19. Analysts' data shows that fields related to cancer and medicine are particularly hard-hit, while areas such as philosophy and art are less affected.

To better understand the scope, ramifications and potential solutions of this metastasizing assault on science, we — a contributing editor at Retraction Watch, a website that reports on retractions of scientific papers and related topics, and two computer scientists at France's Université Toulouse III—Paul Sabatier and Université Grenoble Alpes who specialize in detecting bogus publications — spent six months investigating paper mills.

Co-author Guillaume Cabanac also developed the Problematic Paper Screener, which filters 130 million new and old scholarly papers every week looking for nine types of clues that a paper might be fake or contain errors.

An obscure molecule

Frank Cackowski at Detroit's Wayne State University was confused.

The oncologist was studying a sequence of chemical reactions in cells to see whether they could be a target for drugs against prostate cancer. A paper from 2018 in the American Journal of Cancer Research piqued his interest when he read that a little-known molecule called SNHG1 might interact with the chemical reactions he was exploring. He and fellow Wayne State researcher Steven Zielske began experiments but found no link.

Meanwhile, Zielske had grown suspicious of the paper. Two graphs showing results for different cell lines were identical, he noticed, which "would be like pouring water into two glasses with your eyes closed and the levels coming out exactly the same." Another graph and a table in the article also inexplicably contained identical data.

Zielske described his misgivings in an anonymous post in 2020 at PubPeer, an online forum where many scientists report potential research misconduct, and also contacted the journal's editor. The journal pulled the paper, citing "falsified materials and/or data."

"Science is hard enough as it is if people are actually being genuine and trying to do real work," said Cackowski, who also works at the Karmanos Cancer Institute in Michigan.

Legitimate academic journals evaluate papers before publication by having other researchers in the field carefully read them over. But this peer review process is far from perfect. Reviewers volunteer their time, typically assume research is real and so don't look for fraud.

Some publishers may try to pick reviewers they deem more likely to accept papers, because rejecting a manuscript can mean losing out on thousands of dollars in publication fees.

Worse, some corrupt scientists form peer review rings. Paper mills may create fake peer reviewers. Others may bribe editors or plant agents on journal editorial boards.

An 'absolutely huge' problem

It's unclear when paper mills began to operate at scale. The earliest suspected paper mill article retracted was published in 2004, according to the Retraction Watch database, which details retractions and is operated by The Center for Scientific Integrity, the parent nonprofit of Retraction Watch.

An analysis of 53,000 papers submitted to six publishers — but not necessarily published — found 2% to 46% suspect submissions across journals. The American publisher Wiley, which has retracted more than 11,300 articles and closed 19 heavily affected journals in its erstwhile Hindawi division, said its new paper mill detection tool flags up to 1 in 7 submissions.

As many as 2% of the several million scientific works published in 2022 were milled, according to Adam Day, who directs Clear Skies, a company in London that develops tools to spot fake papers. Some fields are worse than others: biology and medicine are closer to 3%, and some subfields, such as cancer, may be much larger, Day said.

The paper mill problem is "absolutely huge," said Sabina Alam, director of Publishing Ethics and Integrity at Taylor & Francis, a major academic publisher. In 2019, none of the 175 ethics cases escalated to her team was about paper mills, Alam said. Ethics cases include submissions and already published papers. "We had almost 4,000 cases" in 2023, she said. "And half of those were paper mills."

Jennifer Byrne, an Australian scientist who now heads up a research group to improve the reliability of medical research, testified at a July 2022 U.S. House of Representatives hearing that nearly 6% of 12,000 cancer research papers screened had errors that could signal paper mill involvement. Byrne shuttered her cancer research lab in 2017 because genes she had spent two decades researching and writing about became the target of fake papers.

In 2022, Byrne and colleagues, including two of us, found that suspect genetics research, despite not immediately affecting patient care, informs scientists' work, including clinical trials. But publishers are often slow to retract tainted papers, even when alerted to obvious fraud. We found that 97% of the 712 problematic genetics research articles we identified remained uncorrected.

Potential solutions

The Cochrane Collaboration has a policy excluding suspect studies from its analyses of medical evidence and is developing a tool to spot problematic medical trials. And publishers have begun to share data and technologies among themselves to combat fraud, including image fraud.

Technology startups are also offering help. The website Argos, launched in September 2024 by Scitility, an alert service based in Sparks, Nevada, allows authors to check collaborators for retractions or misconduct. Morressier, a scientific conference and communications company in Berlin, offers research integrity tools. Paper-checking tools include Signals, by London-based Research Signals, and Clear Skies' Papermill Alarm.

But Alam acknowledges that the fight against paper mills won't be won as long as the booming demand for papers remains.

Today's commercial publishing is part of the problem, Byrne said. Cleaning up the literature is a vast and expensive undertaking. "Either we have to monetize corrections such that publishers are paid for their work, or forget the publishers and do it ourselves," she said.

There's a fundamental bias in for-profit publishing: "We pay them for accepting papers," said Bodo Stern, a former editor of the journal Cell and chief of Strategic Initiatives at Howard Hughes Medical Institute, a nonprofit research organization and funder in Chevy Chase, Maryland. With more than 50,000 journals on the market, bad papers shopped around long enough eventually find a home, Stern said.

To prevent this, we could stop paying journals for accepting papers and look at them as public utilities that serve a greater good. "We should pay for transparent and rigorous quality-control mechanisms," he said.

Peer review, meanwhile, "should be recognized as a true scholarly product, just like the original article," Stern said. And journals should make all peer-review reports publicly available, even for manuscripts they turn down.

This article is a condensed version of the full six month-long investigation. To learn more about how fraudsters around the globe use paper mills to enrich themselves and harm scientific research, read the full version.

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

At Live Science we know how important online communities are, and we’re always looking for ways to encourage positive discussion around science. That’s why we’re excited to announce that you are now free to comment on most articles published on our site.

Our goal is that the comment section will be the best place for thoughtful analysis and entertaining discussion around science. Together we’re developing a space where you can share your passion and enjoy conversations built on a foundation of respect and common interests.

Our team is dedicated to providing quality content — please keep that in mind and keep disagreements respectful. Not every comment needs to be a debate — it’s fine to just talk — but please approach all disagreements in a spirit of openness and tolerance.

Whenever someone visits the comment section here at Live Science they should find them welcoming and insightful. We want to build a community that you’re proud to recommend to others, and we can only do that together.

So how do you get started?

Commenting on Live Science is easy. First, please read our community guidelines before commenting — these set out the baseline rules and expectations. Then either sign in at the top right of the page or below the article.

Once you’ve done this you can add your thoughts, and if your comments follow our guidelines they will be posted to the site.

In accordance with our Terms of Use, all users must be registered and logged in to leave comments on Live Science.

Please note that not all articles will have commenting available. If this is the case then please do not try to discuss them in other comment sections; they have been closed for a reason and this may be a legal requirement.

Important Information

Comments can be edited or deleted up to five minutes after they are posted.

All of your community settings can be accessed through the notification bell, which is present in the comment section as well as in the header. Here, you can:

See your comment history and any users you are following/that are following you.

Follow/Unfollow users.

Mute users.

See which conversations are most active.

Receive notifications when someone replies or likes your comment.

Receive notifications when a user you follow posts comments.

Receive notifications when there is new activity on a conversation you follow.

Turn on email notifications so you will be notified via email when someone has responded to your comment.

We’re looking forward to building our commenting community with you all. If you have any questions or feedback about the system, feel free to email us at commentmoderation@futurenet.com.

Some parents insist that they could never pick a favorite child — but a new study calls that into question.

A new analysis of 30 studies that collectively included almost 20,000 people revealed that parents are more likely to favor their daughters over their sons. The research also suggests that parents favored children who are perceived to be more agreeable and conscientious than their siblings. The studies included in the analysis were conducted only in North America and Western Europe, and they included predominantly white people, meaning that the results may not be applicable to people from other demographics.

In this context, favoring a child doesn't necessarily mean that parents have "favorites" — rather, they choose to treat certain children in a more favorable way than their siblings, the researchers noted in the study, which was published Jan. 16 in the journal Psychological Bulletin.

"It isn't about the parents loving one child and hating the other," said study co-author Alexander Jensen, an associate professor in the School of Family Life at Brigham Young University in Utah. "It's about being more affectionate with one of them, having more conflict with one of them, or spending more time with one of them," he told Live Science in an email.

Related: Middle children are more agreeable, humble and honest than siblings, new study suggests. The baby of the family would like a word.

It is important to understand these different parent-child interactions because children who receive more favorable treatment from their parents are more likely to have better mental health, increased academic success and healthier family relationships, among other benefits, previous research has shown. The opposite is true for children who receive less favorable treatment.

"A study several years ago suggested that if children understand why they are treated differently, then the differences don't matter," Jensen said. In other words, if a child sees that their treatment is justified, they may be more likely to accept it. For example, an older child may feel left out if their mom spends more time helping their younger sibling with their homework, until they realize that their sibling needs extra help with it.

"I hope parents will use our study as a catalyst to consider how they may treat their children differently, then work to make sure those differences are fair and understood by their children," Jensen said.

In the new analysis, Jensen and colleagues looked at data from 30 scientific papers and 14 databases, which chronicled information on the family dynamics of 19,469 people. Around 67% of these individuals were from the U.S., while the rest were from Western Europe and Canada.

The researchers investigated how specific characteristics of a child correlated with how their parents treated them. This data had been collected in a variety of ways, including via interviews, surveys and at-home observations.

The children's characteristics included factors such as when they were born relative to their siblings, their gender, and their temperament and personality traits, such as extraversion, agreeableness, conscientiousness and neuroticism — the tendency to experience negative emotions. Parents' preferential treatment was measured by how parents interacted with their children, how much money they spent on them or how much control they wielded over them, in regards to having strict or lenient rules.

The study only looked at correlations between child characteristics and differential parental treatment. Therefore, the findings alone cannot explain why parents seem to favor daughters and more-agreeable children over sons and less-aggreeable children, respectively.

That said, agreeable children are likely to be more willing to do what they're asked, meaning that their parents may find it easier to manage them and thus respond more positively towards them, the study authors speculated.

In the future, more research is needed to understand whether these parental preferences also exist in families from a more diverse range of cultures, as well as across different stages of life — for instance, looking at parents' treatment of their kids in adulthood, too.

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.

Black holes are terrifying, monstrous objects with immense gravity that causes them to consume everything that crosses their event horizons.

Yet the physics-breaking power of the space-time ruptures is also part of their draw — sucking in scientists who want to study the role of black holes in sculpting galaxies and those searching for a unified theory of gravity. Here are the most monstrous black hole findings of the year.

Scientists spot an ultra-rare "missing link" black hole hiding in the Milky Way's center

The known black holes that populate the universe fall into two types: those up to a few dozen times the mass of the sun and their supermassive counterparts that can weigh up to 50 billion solar masses. But exactly how the former evolved into the latter is unclear, especially as there have yet to be any confirmed sightings of black holes in their awkward intermediate phases.

Enter a new intermediate black hole candidate, which astronomers spotted inside the IRS 13 star cluster, just a tenth of a light-year from Sagittarius A*, the supermassive black hole at the heart of the Milky Way galaxy. If scientists can confirm its existence, it could give vital clues to how black holes evolve.

A feasting supermassive black hole is consuming material 40 times faster than should be possible

This year, scientists found another clue to how supermassive black holes grow to their unimaginable scales, in the form of the gluttonous monster LID-568.

The James Webb Space Telescope spotted the black hole as it appeared just 1.5 billion years after the Big Bang, and it was gobbling material 40 times faster than its theoretical feeding limit (called the Eddington limit). The discovery could explain why so many giant black holes appear so early in the universe's history.

"Impossible" black holes discovered by the James Webb telescope may finally have an explanation

The finding about LID-568's feeding frenzy was far from the last word on early supermassive black hole formation. Theoreticians also proposed how black holes came to be seeded across the universe without, as they typically do today, emerging from dead stars: by rapidly collapsing pockets of gas that formed primordial black holes.

Most of these tiny singularities evaporated, according to the new hypothesis, but the ones that survived gorged and merged at a breakneck pace to reach their enormous scales.

Tiny black holes could be hollowing out planets and zipping through our bodies

Another theoretical proposal about primordial black holes also made waves this year: the suggestion that they might still exist. Perhaps they're hollowing out planets and zipping through our bodies and buildings, leaving only microscopic traces.

If bits of tiny black holes swarming across the cosmos can be found, they would be immediate candidates for most of the missing matter that seems to exert a gravitational pull yet barely interacts with light.

Biggest black hole jets ever seen are as long as 140 Milky Ways

Some black holes spew infalling matter out again, forming gigantic, near-light-speed plasma jets that can extend for hundreds of light-years. But one black hole jet pair astronomers spotted — named Porphyrion, after a giant in Greek mythology — really took the cake: At 23 million light-years in length, the pair is as long as 140 Milky Way galaxies laid end to end.

Black hole "blowtorch" is causing nearby stars to explode

Black hole jets aren't just incredible features. They're a powerful — yet still mysterious — force for the cosmic monsters to shape the wider universe. For the first time, researchers have observed a black hole jet causing stars in its vicinity to burst in explosions called novas.

Because the stars weren't directly hit by the beam, exactly how the jet is causing the stars to pop is unknown. By searching for answers, astronomers could gain a better understanding of how black holes affect even extremely distant surroundings.

Astronomers discover why some black holes have a "heartbeat"

While feeding, black holes can heat up their "food" to immense temperatures to release enormous X-ray flares that last millions of years. But inside these flares lurks another, strange signal: a regular pulse of light that resembles a heartbeat. By studying one of the flares, astronomers now think they have an explanation for black hole heartbeats: They're produced by shock waves that ripple through black holes' food as they feast.

Event Horizon Telescope reveals why our galaxy's black hole is spinning so weirdly

Our galaxy's central black hole, Sagittarius A*, is a gargantuan tear in space-time that is 4 million times the mass of the sun and 14.6 million miles (23.5 million kilometers) wide. But these are pretty standard proportions for a black hole of this scale. What is unusual about Sagittarius A* is that it's spinning surprisingly fast and it's out of kilter with the rest of the Milky Way.

This year, using the Event Horizon Telescope, which in 2022 captured the first image of our galaxy's black hole, scientists found the answer: Sagittarius A* was likely born from a gigantic collision between two giant black holes, and its lopsided rotation is a key sign of its violent origins.

Scientists spot the first black hole "triple" system

Many black holes exist in binary systems, orbiting a star companion, but researchers have now spotted one orbited by two stars, making it the first black hole triple system ever seen. Beyond creating an entirely new category in its own right, the discovery has serious implications for black hole formation.

Black holes that exist in binary systems are typically thought to have emerged from the gravitational collapse of a star. But astronomers say this triplet could offer firsthand evidence of black holes directly collapsing from gas clouds.

Dormant black hole roars to life

Black holes are typically either active and consuming material around them, or dormant because they have already swallowed everything in their midst. It's rare to see black holes shift between the two states. But astronomers have now spotted a black hole that's waking up after a long slumber.

The reasons for the black hole's reactivation remain unclear, but astronomers hypothesize that it may have begun to capture new material. Alternatively, the light coming from near the space-time singularity star that it has snared and exploded.

Disagreements about research results aren't often aired in the open, but this year saw its fair share of public scientific controversies.

Debates between scientists are usually confined to the pages of scientific journals, with researchers criticizing one another's work via letters and commentaries. Occasionally, though, these disputes spill out into the wider media, and they can range from squabbles over dinosaur bones to huge controversies around key archaeological artifacts.

This year, scientists argued about everything from climate change, to space junk to black holes. Here is our list of 2024's most controversial science stories.

Building world's 1st pyramid

In a preprint study published this summer, researchers proposed that ancient Egyptians built the world's first pyramid — the 4,700-year-old Step Pyramid of Djoser, which sits on Egypt's Saqqara plateau — using a "modern hydraulic system" powered by a long-gone branch of the Nile River. The system comprised a dam, a water treatment plant and a hydraulic freight elevator, the researchers suggested, enabling workers to deliver heavy construction materials to the pyramid building site.

The proposed infrastructure addresses long-standing questions about how ancient Egyptians erected the Step Pyramid of Djoser, which contains 11.6 million cubic feet (330,400 cubic meters) of stone and clay, before the advent of large machinery like bulldozers and cranes. Study lead author Xavier Landreau told Live Science the hydraulic system was "a watershed discovery," but another expert wasn't so sure about the findings.

Julia Budka, an archaeologist specializing in ancient Egypt at Ludwig Maximilian University of Munich in Germany, told Live Science that "scientifically, their hypothesis is not proven at all." Budka added: "My biggest concerns about the study are that no Egyptologists or archaeologists were directly involved and that the authors actually question the use of the Djoser Pyramid as a burial site." (Peer-reviewed research shows the pyramid was in fact used as a burial site.)

Black hole image

A groundbreaking picture of Sagittarius A*, the supermassive black hole that sits at the center of the Milky Way, caused a stir this year, with a study published online in May claiming the image displays important errors. The photo, which was taken with the Event Horizon Telescope (EHT) in 2017 and released in 2022, is the first ever image of our galaxy's central black hole, located 26,000 light-years from Earth.

The image shows an orange, donut-shaped ring of gas against a pitch-black background — but researchers say the ring is distorted due to the way the data for the image were stitched together. The ring should be more elongated than it appears in the image, the researchers said, and the eastern half should be brighter than the western half.

"We hypothesize that the ring image resulted from errors during EHT's imaging analysis and that part of it was an artifact, rather than the actual astronomical structure," study lead author Makoto Miyoshi, an astronomer at the National Astronomical Observatory of Japan, said in a statement at the time.

The EHT team responded to the claims in November saying that their methods were extensively verified, and their results consistent over two days of observations. The team pointed out inconsistencies in the revised image, arguing that Miyoshi and colleagues mistook "the biases in their own methodology as demonstrations of biases" in the original EHT methods.

Global warming's beginning

A study published early this year found Earth is on course to reach 3.6 degrees Fahrenheit (2 degrees Celsius) of warming relative to preindustrial levels by the late 2020s — more than a decade earlier than current projections. Global warming of 2 C is considered a critical threshold to prevent the worst effects of climate change; warming beyond this would greatly boost the likelihood of extreme weather and other destructive impacts.

The study authors said in a news conference that their results mark "a major change to the thinking about global warming," because they bring forward the advent of human-made climate change by four decades, meaning scientists have been underestimating the level of warming all along. The United Nations' Intergovernmental Panel on Climate Change estimates that global warming began around 1900, but the recent study says the start date is more likely to have been in the 1860s.

The authors based their results on climate indicators found in old skeletons of sponges from the Caribbean Sea. But other experts criticized the findings, saying the authors wrongly extrapolated from highly local data to draw conclusions about the whole world. "The study fails to support its global claims with robust evidence, and it fails by a huge margin," Jochem Marotzke, a professor of climate science and director of the Max Planck Institute for Meteorology in Germany, told Live Science.

"Skepticism is warranted here," Michael Mann, director of the Penn Center for Science, Sustainability and the Media, told Live Science. "It honestly doesn't make sense to me."

Weakening Earth's magnetic field

Defunct satellites that burn up as they enter Earth's atmosphere could be releasing dust that interferes with the planet's magnetic field, according to a preprint study that attracted criticism this year. Metal pollution from falling space junk may theoretically create an invisible conductive shell around Earth, weakening the magnetosphere — the bullet-shaped field around Earth that stretches roughly 39,800 miles (64,000 kilometers) above our planet's surface.

The metal pollution, a problem that is being made worse by the unchecked expansion of commercial satellites orbiting Earth, could slice the magnetosphere in half and lead to "atmospheric stripping" down the line, study author Sierra Solter-Hunt, who was then a doctoral candidate at the University of Iceland, told Live Science. Although this is a worst-case scenario, the findings are "really, really alarming," Solter-Hunt said.

Some scientists praised the study for highlighting potential issues arising from spacecraft dust, but others said the results were too speculative or based on flawed assumptions. "Even at the densities [of spacecraft dust] discussed, a continuous conductive shell like a true magnetic shield is unlikely," John Tarduno, a professor of physics and astronomy at the University of Rochester in New York, told Live Science.

Nevertheless, space junk pollution "is not an issue to be ignored," said Fionagh Thompson, a research fellow at Durham University in the U.K. "There is a need to step back and view this as a completely new phenomenon."

Baby T. rex or tiny dino?

A study in January weighed in on a long-standing debate over a set of dinosaur fossils that could belong either to a young Tyrannosaurus rex or to a distinct species called Nanotyrannus lancensis. The study supported the Nanotyrannus hypothesis, based on growth rings on the fossils, and claimed to snuff out the opposing side of the dispute once and for all — but other experts still weren't convinced.

The study authors found that growth rings were closely packed toward the outside of the bones, which is inconsistent with the rapid growth of a dinosaur, and therefore refutes the juvenile T. rex hypothesis, they said. "If they were young T. rex they should be growing like crazy," lead author Nicholas Longrich, a paleontologist and senior lecturer at the University of Bath in the U.K., said in a statement at the time. Instead, the bones showed a pattern consistent with slowing growth, Longrich said.

But some experts remained resolutely team T. rex. "The authors don't seem to have a solid grasp on growth variation in tyrannosaurs," Thomas Carr, a vertebrate paleontologist and an associate professor of biology at Carthage College in Wisconsin, told Live Science. Others said they will sit on the fence until fossils come to light that belong to either a fully adult Nanotyrannus or a young T. rex that definitely isn't Nanotyrannus — at which point comparison work could settle the question once and for all.

Alexander the Great's lost tunic?

A scrap of cloth discovered decades ago in a royal tomb belonged to none other than Alexander the Great, according to a controversial study published in October. Located in Greece, the tomb is generally believed to hold the remains of Alexander's father, Philip II, but the study argues it actually belongs to Alexander's half-brother, Philip III. Therefore, the cloth inside was once part of a sacred tunic worn by Alexander that, after his death, was passed on to Philip III and accompanied him to his grave, the author claimed.

The study's conclusions are based on multiple lines of evidence — such as the art on the tomb's walls, studies of the skeletons found inside and ancient records of garments worn by different kings — but the findings sparked mixed reactions from experts. Some researchers said there is no evidence to support the idea that the cloth formed part of a tunic, while others noted that the author of the study never actually saw the piece of material, discrediting the paper's conclusions.

Another group of researchers, meanwhile, thought the case for the cloth being Alexander's lost tunic was strong.

AI fingerprint-matching tool

A new technique to match fingerprints from separate digits belonging to the same person sparked controversy at the beginning of 2024. It's long been suspected that connecting prints from different digits could help solve criminal cases, but forensic methods so far haven't been able to do so accurately, only reliably linking fingerprints from the same digit.

Researchers used artificial intelligence (AI) to develop a tool that can connect different fingerprints left by the same person 77% of the time, based on similarities between the angles of arches, whorls and loops on each finger. The study in which they detailed their methods was rejected by several journals but was eventually published, receiving mixed reactions from other experts.

Simon Cole, a professor of criminology, law and society at the University of California, Irvine, said the study was "overhyped" and only had "rare and limited use," given that law enforcement routinely takes prints from all 10 digits and can match prints simply by looking at records.

Ralph Ristenbatt, a criminalist and assistant teaching professor of forensic science at Pennsylvania State University, argued the technique could prove useful in certain cases. But more work is needed until the AI tool is accurate enough to be rolled out and used in a court of law.

Megalodon misrepresented?

A new analysis of megalodon fossils published in January found that the long-extinct, supersized sharks looked nothing like researchers previously thought. Reconstructions to date indicated that megalodons (Otodus megalodon) measured around 52 feet (16 meters) long and resembled great white sharks (Carcharodon carcharias), but this body shape "looked very awkward," according to the authors of the new study.

The anatomy of megalodon has remained somewhat elusive because shark skeletons are made of cartilage rather than bone, and therefore don't preserve well as fossils. Scientists mostly only had fossilized teeth and vertebrae to work with, so they often used great white sharks as models to establish what megalodon looked like.

The analysis in January found megalodons were much slimmer and longer than great whites, with a body plan closer to that of a shortfin mako shark (Isurus oxyrinchus). The evidence suggested the meg may have reached 66 feet (20 m) long or possibly slightly more, the authors told Live Science. But other researchers who had previously examined megalodon fossils weren't convinced by the findings.

According to them, the analysis used "circular logic," where an argument uses the assumption that its conclusion is correct to support itself. "The 'elongated body' interpretation is based on a single observation, a comparison with a single analogue, and lacks any statistical tests to support its hypothesis," Jack Cooper, a researcher at Swansea University in the U.K., Catalina Pimiento, also of Swansea University, and John Hutchinson from the Royal Veterinary College in London told Live Science. The study is also impossible to fully verify as the authors held back crucial data, the researchers said.

Middle children, rejoice: A new study finds that you're more agreeable, honest and humble than your older and younger siblings.

But don't crow too loudly at your holiday meal (not that you would, being so humble). The research contradicts previous large studies on birth order and personality and will likely need more research to replicate the findings.

Stereotypes abound

There are plenty of pop-psychology stereotypes about how one's birth order affects personality, from the overachieving first born to the peacekeeping middle children to spoiled babies of the family. But most research has not supported these stereotypes. A 2015 commentary in the journal PNAS noted that studies over two decades found wildly contradictory results, with some showing very strong correlations between personality traits and birth order and others finding none at all. Many of these studies were small, non-representative samples.

In 2015, two studies with large samples were published. One looked at 20,000 people in the U.S., U.K. and Germany and tried to find relationships between birth order and personality traits as measured by the Big Five – five standard psychological categories of personality that are well-supported by research. (They are extraversion/introversion, agreeableness, openness to experience, neuroticism and conscientiousness.) The other study did something similar with a sample of 272,000 U.S. adults who attended high school in 1960 and are part of a long-running study called Project Talent.

Neither study made much of a case for birth order influencing personality. The three-country study found no relationship, while the Project Talent study found a very small relationship between intelligence and being an older sibling, perhaps suggesting that older siblings benefit from teaching their younger siblings. Still, despite this statistically detectable difference, a younger sibling will still score higher on an IQ test than their older sibling in four out of ten cases, the researchers wrote, meaning the finding has limited power to predict intelligence in the real world.

Related: Are these 4 personality types for real?

New dataset

Now, a new study argues that there are differences – and that crucially, they depend on family size. This study, published Monday (Dec. 23) in the journal PNAS, used a different personality measure called HEXACO, which was developed by Michael Ashtona and Kibeom Lee, the two authors of the new study. HEXACO overlaps with the Big Five personality dimensions, but with some differences. Its categories are honesty/humility, emotionality, extraversion, agreeableness, conscientiousness and openness to experience. Agreeableness in HEXACO means a tendency toward flexibility, grace, and forgiveness, whereas agreeableness in the Big Five is defined by warmth and cooperation.

The researchers used data from hexaco.org, where anyone can take a personality test to find out where they fall on this scale. For 710,797 individuals, they had information about birth order. For another 74,920 individuals, they had information about both birth order and number of siblings. (These studies do not differentiate between step-siblings, half siblings or other biological relationships, instead defining siblings as any other children in the household.)

In this dataset, the researchers found that middle children had the highest scores for honesty/humility and for agreeableness, followed by youngest siblings, then oldest, then only children. They also found that the more siblings a person had, the higher they scored in these same traits.

Because religious families tend to have more children, the researchers controlled for religiosity and found that religion explained about 25% of these differences, but that still left birth order and family size responsible for the rest. The differences between siblings are small, but the authors speculate that they could be due to the forced cooperation that occurs in large families.

"A commonsense possibility is that when one has more siblings, one must more frequently cooperate rather than act on selfish preferences," Lee and Ashtona wrote. "This ongoing situation might then promote the development of cooperative tendencies generally."

These findings are not likely to be the last word in birth order research, however. In 2020, for example, another study searching for differences between only children and children with siblings turned up no differences in narcissism. And a 2019 study comparing only children and people with siblings using HEXACO found only vanishingly small differences.

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

From speculation that JFK's assassination was an "inside job" to claims that vaccines contain microchips, the world is awash with conspiracy theories. The term was coined in the 1860s, appearing in a letter in The New York Times that discussed British support during the Civil War.

Fast-forward 150 years, and conspiracy theories are more prevalent than ever, which can be put down to the rise of social media, the spread of disinformation and a number of psychological factors — including a need to make sense of the world.

But how much do you know about the wildest conspiracy theories? Test your knowledge on the Illuminati, faked moon landings, flat Earth and even more bizarre claims in our conspiracy theory quiz. Make sure you login to add your name to the leaderboard, and if you need a hint, tap the yellow button.

More science quizzes

—Evolution quiz: Can you naturally select the correct answers?

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

—Crocodile quiz: Test your knowledge on the prehistoric predators

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

—Solar system quiz: How well do you know our cosmic neighborhood?

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.

Throughout much of human history, we have made sense of the passage of time by dividing it into units. Different cultures have done this differently, but in modern times, the most common way is to break time into seconds, minutes, hours, days, weeks and years.

But how many weeks are there in a year?

Generally, there are 52 weeks and one additional day in a regular year. In a leap year, which occurs almost every four years, there are 52 weeks and two additional days.

When did we decide there are 52 weeks in a year?

The story of how we arrived at these timekeeping rules is rather complex. Early methods of timekeeping date to as early as 11,000 years ago. An Australian Aboriginal stone arrangement suggests the people who constructed it used the patterns of the sun to track the passage of time.

"The biggest driver [for keeping time] was probably religion," Demetrios Matsakis, former chief scientist at the Department of Time Services of the United States Naval Observatory and now chief scientist at Masterclock, Inc. told Live Science. "The Egyptians, Sumerians and others needed to recite certain prayers at certain times of the day and night."

Since then, cultures have employed both the positions of the sun and the moon to chronicle the passing of time. Some calendars have been based solely on the sun or the moon and others have attempted to combine the two.

"The sun is much better [as a means of calculating time] because the moon's orbit is very irregular due to the interplay between the gravitational fields of the Earth and the sun," Matsakis said.

The Gregorian calendar, the most commonly used calendar worldwide, is a solar calendar based exclusively on the movement of Earth around the sun. It is derived from a calendar Julius Caesar instituted in 46 B.C. The Julian calendar calculated the length of the year at 365.25 days, so it added an extra day every four years. However, a year is actually 365.2422 days. The Julian calendar failed to account for about 11 minutes, which compounded over time.

By the time the discrepancy was noticed in the 1600s, around 10 additional days had accrued in the calendar. This became a concern for the Catholic Church, which desired to keep a precise calendar to maintain an accurate observance of holidays.

"Over the centuries that difference added up, and Pope Gregory XIII was worried that Easter was being celebrated at the wrong time," Matsakis said. The celebration of other holidays was calculated by their distance from Easter, creating additional complications for the church.

The pope determined that the problem should be corrected by skipping leap years in any centurial year not divisible by 400. Gregory decreed that Oct. 4, 1582 would skip directly to Oct. 15, thus correcting for the extra days that resulted from the slight inaccuracy in the Julian calendar.

While some countries quickly adopted the new calendar, others did not. Some, such as England, refused due to religious reasons — the nation's Protestant faith conflicted with edicts issued by the Catholic Church. The United Kingdom did not adopt the new system until 1752. Others had long observed alternative calendrical systems. China, for example, had long used a lunar calendar and did not adopt the Gregorian calendar until 1912. The country did not actually put it into wide use until 1929.

As a result, many documents in the years following Pope Gregory's decree listed both Old Style dates, which reflected the Julian calendar, and New Style dates, which reflected the Gregorian calendar, in order to avoid confusion.

Later, the calendar was further refined to be even more accurate than the Gregorian. "In 1923, on the advice of the Serbian astronomer Milutin Milanković, the leap year system was changed again," Matsakis said.

This time, any year not divisible by 100 was not a leap year, with the exception of those that left remainders of 200 or 600 when divided by 900. The Milanković calendar will align with the Gregorian calendar until 2800. Despite the increased accuracy, it has only been adopted by certain branches of the Eastern Orthodox Church.

On July 16, 1945, the U.S. conducted the world's first nuclear bomb test in the New Mexico desert as part of the Manhattan Project, which led to the detonations of atomic bombs on Hiroshima and Nagasaki just weeks later. Since then, at least seven other countries have tested their own weapons, unleashing radiation around the world.

But how many nuclear bombs have actually gone off?

Although the exact answer isn't known, scientists estimate that at least 2,056 nuclear weapons have been tested. According to the Arms Control Association, the U.S. has tested 1,030 nuclear bombs and utilized two in warfare, the Soviet Union/Russia has tested 715, France has tested 210, the United Kingdom and China have each tested 45, North Korea has tested six, India has tested three and Pakistan has tested two. (A suspected additional test, known as the Vela incident, would bring the tally to 2,057.)

While nuclear testing has not been common since the 1990s, it has had extensive political, environmental and public health impacts that extend to this day. The international community now condemns it. But for almost 20 years, from 1945 to 1963, nuclear testing was commonplace for many countries as they vied for status as world powers.

Nuclear testing skyrocketed during the Cold War between the U.S. and the USSR following World War II. According to the Arms Control Association, 1962 holds the record for most tests conducted in one year, when 178 nuclear tests were conducted, of which 97% were set off by the U.S. and the USSR. The U.K. also conducted two tests, and France conducted one.

Related: What happens when a nuclear bomb explodes?

But 1962 was also a key turning point for nuclear tensions. That same year, the Cuban Missile Crisis marked the closest the U.S. and USSR came to nuclear conflict. Many people around the world had begun protesting the nuclear arms race, and the public began to understand the impact testing had on health.

A landmark 1961 study published in the journal Science tested baby teeth in children in St. Louis for strontium-90, a cancer-causing radioactive isotope created by nuclear explosions and easily absorbed by children. The study showed that strontium-90 levels were 50% higher in the baby teeth of children in the 1960s than in the 1950s, despite St. Louis being hundreds of miles away from the blast sites in Nevada.

The study generated vast public concern about testing, and helped push the U.S. into signing the Limited Nuclear Test Ban in 1963, Tilman Ruff, the former co-president of International Physicians for the Prevention of Nuclear War, told Live Science in an email.

Less than a year later, in 1963, the Limited Test Ban Treaty was introduced to the United Nations and wholeheartedly adopted. The treaty prohibited nuclear tests in the atmosphere, in outer space and underwater, which were all drastically more harmful than underground tests.

"By 1963, nearly two decades of bomb testing had poisoned the air, land and water with hundreds of radioisotopes," Robert Alvarez, an expert with the Bulletin of the Atomic Scientists, wrote in an email to Live Science.

The world had seen the devastating impacts of nuclear testing gone-awry. During the 1954 Castle Bravo test, unfavorable wind conditions and unexpectedly high radiation yields caused a local population in the Marshall Islands to be exposed to the near-lethal radiation doses, the highest ever following a single nuclear test, according to an article published in the journal International Review of the Red Cross. "The Rongelap Atoll in the Marshall Islands remains a radiological hazard, because of life-threatening fallout from the 1954 Bravo test," Alvarez said.

In all, 108 countries, including the U.S. and the USSR, signed the Limited Test Ban Treaty, and an era of slow disarmament began. Still, hundreds of nuclear bombs would continue to be tested underground for decades to come. Countries like China, India, Pakistan and North Korea also started testing nuclear bombs, despite the efforts of the Non-Proliferation Treaty of 1968 to limit the growth of global nuclear weapons programs.

It wasn't until the Comprehensive Nuclear-Test-Ban Treaty (CTBT) was proposed in 1996 that testing slowed to a standstill. While technically not ratified into law, it has been signed by 187 countries.

Related: How radioactive is the human body?

The CTBT's monitoring system also ensures that nuclear testing can't be hidden. This system, put in place when the CTBT was signed in 1996, uses 321 stations equipped with seismic, hydroacoustic, infrared and radionuclide technologies to detect nuclear testing worldwide. This monitoring system encourages countries that haven't signed the CTBT to disclose their nuclear testing.

The most recent nuclear test was conducted in 2017 by North Korea, which has not signed the CTBT. The CTBT organization's monitoring system recorded the test, which measured at least 140 kilotons, Alvarez wrote — eight times more powerful than the bomb dropped on Hiroshima.

How have nuclear bombs and tests affected our planet?

"The concern and protests of people worldwide about radioactive fallout from nuclear testing has played a major role" in shutting down nuclear testing programs, Ruff said. As nuclear testing continued, science revealing the detrimental effects on the health of people and the environment grew. A 2006 study estimated that 22,000 additional radiation-related cancers and 1,800 additional deaths from radiation-related leukemia were expected to occur in the United States from nuclear testing-related fallout of the 1950 and 1960s.

"For people in the immediate vicinity and downwind of nuclear test explosions, nuclear testing has had profound and long-term effects on their health and communities," Ruff said.

While the U.S. utilized multiple testing sites in Nevada, New Mexico and Colorado, its most powerful bombs were tested in the Marshall Islands, in the Central Pacific Ocean. Starting in 1946, the islands and their inhabitants experienced "the equivalent of 1.6 Hiroshima bombs each day over the twelve years of the tests," according to the International Review of the Red Cross article, which continued even after the Castle Bravo test disaster.

On top of the health hazards, nuclear testing in places like the Marshall Islands also created "broader social effects of displacement, loss of use of traditional lands for cultural and food gathering purposes, social stresses and disruption, and impoverishment," Ruff said.

However, day-to-day radiation across the U.S. has fallen dramatically since the end of atmospheric nuclear testing, according to the Environmental Protection Agency.

Could nuclear testing start again?

Many countries still have nuclear weapons, even if they aren't testing them. The world's nine current nuclear states — China, France, India, Israel, North Korea, Pakistan, Russia, the United Kingdom and the United States — have approximately 13,000 nuclear warheads combined.

North Korea's most recent nuclear test set off a wave of concern from South Korea, which was heightened by the intensive missile tests North Korea conducted in 2022 and 2023. For the first time, South Korea suggested that developing its own nuclear program may be a possibility.

If South Korea or other nuclear-armed countries decide to test their weapons, it would likely prompt other nuclear-armed countries to restart their nuclear tests as well.

"Resumption of nuclear testing would be an extremely provocative and backwards step for the prospects of peace," Ruff wrote.

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!

Chances are, you know someone with a killer ghost story. You might even believe you've encountered a ghost yourself. However, considering there's no scientific evidence that ghosts exist, why do some people think they've seen or heard them?

Christopher French, a professor emeritus of psychology at Goldsmiths, University of London, recently wrote a book about the science of the paranormal and said ghost sightings are often "sincere misinterpretations of things that do have a natural explanation."

"Just because you can't think of an explanation doesn't mean there isn't one," French told Live Science.

French is a skeptic who explores non-paranormal explanations for ghostly encounters. These explanations include hallucinations, or perceptions of things that aren't there; false memories, or recollections of events that didn't happen; and pareidolia, or the tendency to see a face or something significant in an inanimate object or random pattern.

The human brain is prone to missing things and misremembering events, and it can jump to conclusions when trying to understand an ambiguous experience. This is especially true when a person wants to believe they've seen a ghost or another legendary creature, Live Science previously reported.

Related: Are ghosts real?

There are also some medical conditions that make perceived ghostly encounters more likely. One area of study for French is a disorder called sleep paralysis, in which people think they've fully woken up but are unable to move, often while sensing an evil presence.

"It's as if your mind wakes up, but your body doesn't," French said. "You've got this interesting mix of normal waking consciousness and dream consciousness, and the contents of the dream are coming through into waking consciousness. The results can be absolutely terrifying."

French noted that if someone gets sleep paralysis without having any prior knowledge of the disorder, then it's not irrational for that person to assume they've had a supernatural experience. However, even during sleep paralysis, when humans are at the mercy of their dreams, the presence people encounter is often a shadowy figure in the corner of the room.

Movies depict ghosts as full-bodied translucent humans, but these kinds of sightings make up only a small minority of perceived paranormal reports. Johannes Dillinger, a professor of early modern history at Oxford Brookes University in the U.K. is working on understanding the types of ghosts people have believed in over the centuries in Western society and culture. He said that the most commonly reported haunting is an unseen poltergeist.

"Many, many ghosts over the centuries were mere poltergeists, meaning they remained invisible throughout," Dillinger told Live Science. "We only think they are there because we hear strange noises, usually at night, that are difficult to explain."

Dillinger found that prior to 1800, people believed that ghosts had important unfinished business, but in a much more literal sense than we might think of today. "Ghosts usually wanted people to find their treasures and put them to some good use," Dillinger said.

Perceived ghosts have become more personal since then. The 19th century marked the rise of spiritualism and a belief that humans could communicate with ghosts and spirits, according to the Science History Institute, a nonprofit that promotes the history of science.

Dillinger noted that people's beliefs changed from ghosts demanding things of the living to the living expecting to be consoled or comforted by the dead. However, throughout all of this, ghosts have remained, above all else, an explanation that people readily accept for strange noises in the dark.

"The ghost is really that thing that goes bump in the night," Dillinger said.

The weekend is here, and what better time to look back at the week in science news by testing your knowledge on what's happened on this planet and beyond.

There is no time limit on the quiz, and if you need a hint you can get one by tapping the lightbulb in the top right corner.

We hope you enjoy it, and be sure to share your results with your friends and followers on social media.

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.