About 800 years ago, two people were buried in an embrace in a prominent church in Poland. Now, a new DNA analysis of the "hugging skeletons" reveals that both individuals were women and that they were not genetically related.

The discovery, which researchers say is the first known same-sex double burial in medieval Poland, raises questions about the women's relationship.

"The discovery of an atypical burial in such a unique setting naturally raised questions about the nature of the relationship between the individuals buried together in a single grave," Agata Cieślik, a biological anthropologist at the Ludwik Hirszfeld Institute of Immunology and Experimental Therapy in Poland, told Live Science in an email.

Mysterious double burial

The skeletons were uncovered during archaeological investigations at the 13th-century Cathedral of the Exaltation of the Holy Cross in Opole, Poland, between 2022 and 2025.

One of the individuals had been buried according to Christian rites typical for the time: lying on their back, with their arms placed along their body. The other person had been placed on their side, with one arm beneath the other person's head, as if in an embrace. Based on the burial positions, the researchers think the people were interred simultaneously.

Typically, double burials of adults are interpreted as married couples. However, assumptions based on body position and physical sex estimation can be misleading. So in a new study, published in the September issue of in the Journal of Archaeological Science: Reports, Cieślik and her colleagues analyzed the two skeletons' DNA to better understand their relationship.

They extracted DNA from the bones and reconstructed parts of the individuals' genetic code, study co-author Joanna Romeyer-Dherbey, a postdoctoral DNA researcher at Kiel University and Yale University, told Live Science in an email. "We then sequence these fragments and use computational tools to reconstruct parts of the genetic code," Romeyer-Dherbey explained, comparing the process to "trying to reconstruct a book after it has been shredded into countless tiny pieces."

The DNA analysis confirmed that both skeletons were female and that they were not closely related, making the grave the first genetically confirmed same-sex burial in medieval Poland. But the researchers are unsure why two unrelated adult women were buried together.

Some unusual interments in the medieval period were intended to ritualistically prevent the dead from returning or causing harm. These feared individuals — sometimes called "revenants" — were typically buried in isolation and in unholy ground, and were often decapitated or weighed down with stones. But the women's burial next to the cathedral walls ‪—‬ a position often reserved for kings and local notables ‪—‬ and the lack of other evidence of protective rituals suggest that these women were not marginalized by society.

Medieval legal and religious sources harshly condemned same-sex partnerships, often punishing them with execution. If these women had been suspected of being lovers, they would not have been afforded such a prominent grave, the researchers wrote in the study.

The women's exact connection to each other remains a mystery, but past relationships came in diverse forms.

"People might have been connected through religion, shared households, economy, or work, which researchers term 'fictive kinship,'" Cieślik explained. "These socially recognized bonds functioned in ways similar to family ties and might have been reflected in the funerary practices."

According to the study, future genetic analysis of other medieval graves could provide insight into whether such same-sex burials were isolated incidents or part of a larger trend.

In the meantime, the Opole excavations revealed many artifacts, such as coins, jewelry, animal bones and pottery fragments that are still under investigation. "Future analyses will help us better reconstruct the historical landscape and everyday life of medieval Opole," Cieślik said.

A Stone Age woman buried with male-associated artifacts in what is now Hungary is revealing that her society embraced complex identities and flexible gender roles 7,000 years ago, a new study finds.

In the study, published Feb. 16 in the American Journal of Biological Anthropology, researchers analyzed 125 skeletons from two cemeteries in eastern Hungary that were in use from 5300 to 4650 B.C. Their goal was to compare traces of repeated activities found on the bones, and examine burial positions and grave goods, which together could shed light on gender roles in this Neolithic society.

The analysis focused on activity-related skeletal changes to gain insight into past people's overall physical workload, upper-limb overuse, and toe hyperextension (which can result from a kneeling posture). While all of the Stone Age men and women had high overall physical workloads and engaged in activities involving kneeling, the researchers discovered that the male skeletons had evidence of right-sided upper-limb overuse — possibly related to throwing movements — that indicated differences in men's and women's use of their arms.

Men and women were also buried differently. In one cemetery, most female skeletons were placed on their left side and were buried with shell bead belts, while most male skeletons were found on their right side and were interred with polished stone tools. But according to the study, two male skeletons and five female skeletons were buried in ways that didn't align with expectations, revealing that the association between biological sex and body position in death was not absolute.

One older adult female burial was particularly unusual. Hers was the only female skeleton the researchers found buried with polished stone tools, and her toes revealed a kneeling activity pattern more like that of the males in the cemetery. According to the researchers, this burial suggests that "females may have assumed roles traditionally associated with males" in the society and that gender roles "were fluid and shaped by multiple intersecting factors."

Study first author Sébastien Villotte, a researcher at the French National Center for Scientific Research, told Live Science in an email that there is no clear evidence this woman had a unique social role, such as shaman. The other people who were buried in ways that did not align with their biological sex may have had "individual trajectories that do not fit in with an 'ideal' pattern," Villotte said. "This is the period in Central Europe when people began to express previously existing gender roles in a new arena."

Stone Age quiz: What do you know about the Paleolithic, Mesolithic and Neolithic?

This round, silver pendant was found in a 10th-century elite woman's burial in Sweden in 1920 and is the only known depiction of a pregnant Viking.

The artifact, known as the Ash Pendant, is in the collection of the Swedish History Museum. It is about 1.5 inches (4 centimeters) in diameter and made out of gilded silver. A ring partially encloses a female figure, who stands with her legs spread and hands clasped under her pregnant belly. Although the top of the pendant is worn down, lines above the woman's head suggest a crown or headdress. The woman wears a cloak buttoned at the neck and a pearl-like beaded accessory.

The pendant was discovered by Swedish archaeologist T.J. Arne in his 1920 excavation of several burial mounds at the site of Aska. Dozens of artifacts were found in the grave, including eight other pendants, four silver rings, a bone game board and an Islamic silver coin. Based on the presence of rivets and nails, the excavators suspected the woman was buried in a wooden casket that decomposed over time, and her bones suggest she was a young or middle-aged adult. It's unknown if she was pregnant or giving birth when she died.

There is some disagreement about what the unique Ash Pendant may signify about the deceased Viking woman.

According to the Swedish History Museum, the pendant may depict the Norse goddess Freyja, who was associated with pregnancy and childbirth. Freyja wore a special necklace called the Brísingamen, the descriptions of which closely match the button clasp and rows of beads on the Ash Pendant. The pendant may therefore have been a talisman for the woman in the grave.

But the Aska site also features a large, flat-topped mound that might have been the foundation for a "royal hall," according to archaeologist Martin Rundkvist, meaning the people buried in the graves were "petty royalty." They appear to have passed down the silver pendants, including the Ash Pendant, as heirlooms over several generations.

Given the range of artifacts discovered in the woman's grave, including a wolf-headed iron staff and the series of heirloom pendants, the woman may have held a prominent role as a practitioner of magic or ritual, archaeologist Neil Price has argued.

And because later graves in the Aska area lack similar ritual objects, according to a study by archaeologist Hide Gustafsson, this may mean that the Viking woman buried in the mound was the last pagan practitioner of her kind before the introduction of Christianity to the region, and that her Freyja pendant was buried with her.

For more stunning archaeological discoveries, check out our Astonishing Artifacts archives.

When archaeologists find ancient human remains, they often try to determine if the person was male or female based on their bones.

So how do archaeologists figure out the sex of the individual from their skeleton, and how accurate are their techniques?

"Overall, we're looking at shape and size differences between the sexes," Sean Tallman, a biological anthropologist at Boston University, told Live Science, but "no one method is 100% accurate."

Archaeologists often take measurements of long, slender bones, like the femur and tibia (which make up the leg), and then use statistical methods to predict the person's sex.

"On average, males are about 15% larger than females," Kaleigh Best, a biological anthropologist at Western Carolina University, told Live Science. But many variables — such as diet, genetics, disease and environment — go into body size, so there can be wide variation even among people of the same sex.

Related: What is the maximum number of biological parents an organism can have?

Most measurement-based techniques assume that males are larger and taller than females, and sex predictions from measurements are 80% to 90% accurate. But if the skeleton's pelvis is well preserved, simply looking at certain features of it is generally a more accurate method than relying on measurements of leg bones.

The main method of estimating the individual's sex from the pelvis is called the Phenice method, named after the anthropologist who proposed it in the 1960s. Differences in the shape of the pubic bone at the front of the pelvis correlate with a person's sex — a taller pubic bone, for example, is more likely to be from a male individual, while a wider one is more likely to be from a female. A well-trained archaeologist can predict the sex of a skeleton with about 95% accuracy with this method.

Ancient DNA analysis is also an accurate chromosomal sex estimation method, in which scientists identify the sex-linked variant of a gene related to tooth enamel production. This technique now reaches about 99% accuracy, even in archaeological skeletons. However, since DNA degrades over time, not every archaeological skeleton can be analyzed in this way.

In spite of this high accuracy rate, many archaeologists say that estimating whether a past person was male or female based on their bones alone may miss other aspects of biological sex, which is a result of the interplay between chromosomes, hormones, gonads and gametes. (Gender, in contrast, is a cultural construct that reflects self-identity, societal roles and pressures.)

"Sex is not binary, but it may be bimodal," Donovan Adams, a biological anthropologist at the University of Central Florida, told Live Science. Bimodal in this context means that if you were to plot sex on a graph, there would be two "humps" for male and female on each end of the graph. But the overlap between the two groups in the middle would represent people who are described as intersex.

"About 1.7% of the population is some form of intersex," Virginia Estabrook, a biological anthropologist at the University of Maryland, Baltimore County, told Live Science, which is "slightly less than 1 in 50 people."

Some examples of intersex conditions include congenital adrenal hyperplasia (CAH), an over-production of male hormones that can make female genitalia look ambiguous at birth; Klinefelter syndrome, or XXY sex chromosomes, resulting in small testes and enlarged breasts in people born male; androgen insensitivity syndrome, in which a person may be born with female-type external genitalia but no internal reproductive organs; and 5α-Reductase 2 deficiency; in which an infant that appears female at birth later develops a penis and testes. And people may have other forms of sex chromosome mosaicism, with XX chromosomes in some cells and XY in others.

For example, Estabrook studied the skeleton of Revolutionary War hero Casimir Pulaski, who died in battle in 1779. His skeleton showed several bony traits that are more typical in female-patterned growth and development, Estabrook said, but historical records clearly show he lived his life as a man. One possible explanation for this discrepancy may be CAH, in which chromosomally female infants have genitals that look more like male genitals. People with CAH produce increased androgens and can grow facial hair.

The case of the intersex general is relatively unique, Estabrook said, "because ordinarily when we encounter skeletons in archaeology, we don't know who these people were."

Understanding who an ancient person was can be stymied not just by the limitations of osteological sex estimation but also by the variable of gender.

Most aspects of a person's identity — from the sports team they support to the gender they adopt — are not something they are born with. "You have to perform identity all throughout your life," Adams said. Those life experiences, including behaviors like wielding a bow-and-arrow or kneeling to grind grain that are often gendered, may leave marks on an ancient skeleton that can muddy the waters — especially because we only imperfectly understand past cultures.

The complexity of both sex and gender means that sometimes archaeologists' interpretations are wrong.

At Pompeii, for example, DNA analysis revealed that a set of skeletons assumed to be a mother and her biological child were actually a man and unrelated child, and in 2019, a Viking burial replete with weapons was found to be chromosomally female rather than male.

Though DNA analysis can dramatically increase the accuracy of chromosomal sex assignment, that doesn't necessarily mean archaeologists have solved the problems of estimating sex from ancient human remains.

"It's really hard to separate ourselves from that binary system," Tallman said, "but there's a ton of overlap between females and males."

Estabrook agreed. "Every way that we try to put a strict, solid line of demarcation on biological sex, there are people who fall outside of those lines," she said.

Another issue is that archaeologists still lack information on intersex conditions because there hasn't been much research into the potentially 1-in-50 people who have one.

"Future work will be greatly affected by the availability of federal funding to do this type of research," Tallman said, "and that could limit these nuanced perspectives that we need to interpret behavior and biology from skeletal remains and from archaeological sites."

Scientific advances have made it easier to determine limited aspects of sex from ancient skeletons, Best said, but figuring out a person's identity from their skeleton "is actually a lot more complicated than we once thought it was."

You're holding two wrinkly human brains, each dripping in formaldehyde. Look at one and then the other. Can you tell which brain is female and which is male?

You can't.

Humanity has been hunting for sex-based differences in the brain since at least the time of the ancient Greeks, and it has largely been an exercise in futility. That's partly because human brains do not come in two distinct forms, said Dr. Armin Raznahan, chief of the National Institute of Mental Health's Section on Developmental Neurogenomics.

"I'm not aware of any measure you can make of the human brain where the male and female distributions don't overlap," Raznahan told Live Science.

But the question of how male and female brains differ may still matter, because brain diseases and psychiatric disorders manifest differently between the sexes. Disentangling how much of that difference is rooted in biology versus the environment could lead to better treatments, experts argue.

There are many different disorders of the brain — psychiatric and neurologic diseases — that occur with different prevalence and are expressed in different ways between sexes, said Dr. Yvonne Lui, a clinician-scientist and vice chair of research in NYU Langone's Department of Radiology. "Trying to understand baseline differences can help us better understand how diseases manifest."

Now, thanks in part to artificial intelligence (AI), scientists are starting to reliably distinguish male and female brains using subtle differences in their cellular structures and in neural circuits that play a role in a wide range of cognitive tasks, from visual perception to movement to emotional regulation. Other studies point to sex-based differences in human brain structure that may be present from birth, and still other, lab-based research in animals points to sex-based differences in how brain cells fire at a molecular level.

What's still completely unclear is to what extent these differences matter. Do they change how people's brains function or how susceptible they are to disease? Should they dictate which treatments doctors offer to each patient? Even as scientists pinpoint subtle brain differences between females and males, their research inevitably runs up against tricky questions of how sex, gender and culture interplay to sculpt human cognition.

Right now, it's impossible to answer these big questions. But ongoing and future research — focused on lab animals, human chromosomes and brain development, and subjects followed from youth through adulthood — could start to reveal how these sex-based differences concretely affect cognition, and ultimately, the development of diseases of the brain.

Why study sex-based brain differences?

Historically, scientists used purported brain differences to make sweeping statements about how men and women think and behave and to justify sexist beliefs that women were innately less intelligent and less capable than men.

While that early research has been discredited, modern studies still find cognitive differences between men and women — at least on average. For example, men reportedly perform better on tests of spatial ability, while women are better at interpreting the facial expressions of others. But men and women are raised and treated very differently in society, so what's at the root of these differences? Is it nature or nurture, or both?

"It's actually incredibly difficult in humans to … causally distinguish how much of a sex difference is societally or environmentally driven," Raznahan said. "We have all of these assumptions and biases that sort of slip into our heads through the back door without us realizing."

Given the dubious history of studying sex differences in the brain, and the logistical difficulty of doing it the right way, one might wonder why scientists bother. For many, it's because neurological diseases and psychiatric conditions seem to play out differently in males and females, and both biological and environmental factors could explain why that is.

Data suggest women experience higher rates of depression and migraine than men do, while men have higher rates of schizophrenia and autism. About twice the number of men develop Parkinson's disease than women do, but women with the condition tend to have faster-progressing disease. All these data come from studies that don't necessarily distinguish sex from gender — "sex" describes biology, while "gender" reflects self-identity, as well as societal roles and pressures. Lumping the two concepts together muddies our understanding of why a given difference exists.

For instance, pubescent girls are more likely to experience depression than boys are, which may be related to how their maturing brains handle stress or the possibility that they encounter more stressful events than boys do at that age. Conversely, do boys' brains make them resilient against depression, or are they actually going underdiagnosed due to social stigma? The answers to these questions point to different solutions.

Large-scale structures, negligible differences

Thanks to brain-scanning techniques like MRI, scientists have found subtle sex differences in the size, shape and thickness of various brain structures, as well as differences in networks that link different parts of the brain.

But these differences are small to negligible when you account for the average size difference between males and females, argues Lise Eliot, a professor of neuroscience at the Rosalind Franklin University of Medicine and Science and author of "Pink Brain, Blue Brain" (Houghton Mifflin Harcourt, 2009).

Eliot and colleagues recently looked at about 30 years of studies, finding that, on average, male brains are 6% larger than female brains at birth and grow to be 11% larger by adulthood. This makes sense because average brain size scales along with average body size, and male bodies tend to be larger. But when you take this overall size difference into account, subtler structural differences between male and female brains shrink to the point of negligibility, the researchers concluded.

"There are maybe species-wide sex differences in the brain, but so far, they haven't been proven," Eliot told Live Science. "And so if they exist, they must be pretty small."

Nonetheless, some scientists have reported differences that they say don't scale with body size. Some examples came from a research group who'd crunched MRI data from over 40,000 adult brains scanned for the UK Biobank, a repository of medical data from 500,000 adults in the United Kingdom.

In that study, males had a larger thalamus, a relay station for sensory information. They also had a larger putamen, which helps control movement and forms part of a feedback loop that tells you whether a movement was well executed. Females, on average, had a larger left-side nucleus accumbens, part of the brain's reward center, and a bigger hippocampus, the storage site for short-term memories of facts and events that also helps transfer the information to long-term memory.

But neither this nor other studies have revealed a specific feature that reliably distinguishes a given male brain from a female brain, since the size ranges seen in each sex largely overlap, Raznahan and colleagues noted in a letter responding to that study.

For the few size differences that do exist, it's currently impossible to say whether they explain any differences in cognition linked to sex, or alternatively, whether they actually make males' and females' cognition more similar, the letter authors noted. Perhaps male and female brains operate slightly differently to reach the same output — to "counterbalance" differences in hormones or genetics that may affect brain function, they wrote.

"When we're just talking about describing a difference in a measurement, that's not saying anything about whether it's got any functional relevance at all," Raznahan emphasized.

AI finds subtle differences

While large-scale structural features might not distinguish male and female brains, AI is helping to uncover other, subtler features that may differentiate the two. Some of these differences appear on the level of the brain's microstructure, meaning its individual cells and components of those cells.

For instance, a study published in May 2024 used different AI models to analyze brain scans from 1,030 young adults ages 22 to 37 years old. The research primarily focused on white matter, the bundles of insulated wiring that run between neurons. "I believe ours is the first study to detect brain microstructural differences between sexes," said Lui, who co-authored the study.

The AI models analyzed differences in both local landmarks in the brain — such as the corpus callosum, which connects the brain's two halves — and the highways that connect distant cells. It also looked at differences in how the white matter was bundled together, as well as in how dense and well insulated those bundles were.

The algorithms accurately predicted the sex of the subject tied to a given scan 92% to 98% of the time. That remaining gap in accuracy likely comes down to the "huge amount of variance in humans," Lui said.

No single part of the brain could be used to make predictions; one model relied on 15 distinct regions of white matter. All models showed some consistencies, though, with the largest white matter structure that crosses the midline, the corpus callosum, standing out as key.

From birth

Lui and colleagues' study was not designed to address how an individual's upbringing or environment shapes the brain. Nor did it aim to disentangle biological differences in the brain from those rooted in gender.

Sex describes biological differences in anatomy, physiology, hormones and chromosomes. Sex traits are categorized as male or female, although some people's traits don't fit neatly in either category. Gender, on the other hand, is cultural. It encompasses how people identify and express themselves, as well as how they are treated and expected to behave by others. Genders include man and woman, as well as others, including those that fall under the umbrella term nonbinary or are unique to specific cultures, like the māhū of Hawai'i.

Historically, studies have conflated sex and gender. To tease these factors apart and see how each manifests in the brain, it would be helpful to follow people over time as their brains are developing — and new research is beginning to do just that.

For example, a 2024 study looked at average brain volume in over 500 newborns: Males' brains were 6% larger overall, even after accounting for differences in birth weight, and females had larger gray-to-white matter ratios. (Gray matter, the cell bodies of neurons, is primarily found in the outer layer of the brain, called the cortex.) That average difference in gray matter is also seen in adults, which makes sense given that larger brains need more white matter to relay signals between far-apart cells.

Statistically, these big-picture brain differences were more significant than differences seen in smaller structures. Females had larger corpus callosa, as well as more gray matter around the hippocampus and in a key emotion-processing hub called the left anterior cingulate gyrus (ACG). Males had more gray matter in parts of the temporal lobe involved in sensory processing, as well as in the subthalamic nucleus, key for movement control. But sex could only explain a fraction of the variance seen in these structures.

Some of these brain differences are "present from the earliest stage of postnatal life" and persist into adulthood, the authors noted. This applies mostly to the global differences, but also potentially to some of the smaller ones. For example, some studies — but not all — show that the left ACG is also larger in adult females, not only in babies.

Durable differences present from birth are likely sex-based. But differences that emerge or disappear in later life, like those in the hippocampus, may be influenced by the environment, or else reflect sex differences in development, including hormonal shifts in puberty.

Gender and sex

Studies like this can help tease apart the influence of sex and gender on the brain. At present, there's a "massive gap" in our understanding of how these factors shape the brain independently and in tandem, said Elvisha Dhamala, an assistant professor of psychiatry at the Feinstein Institutes for Medical Research in New York.

Dhamala and colleagues recently aimed to fill in that gap using data from the Adolescent Brain and Cognitive Development (ABCD) study, an enormous U.S.-based study of brain development and child health. They incorporated functional MRI (fMRI) scans from nearly 4,800 children; fMRI tracks blood flow in the brain to give an indirect measure of brain activity. Each child joined the study at age 9 or 10 and will be followed for 10 years, which will enable follow-up studies.

The fMRI scans highlighted linked brain areas, or networks that lit up as the children did different tasks, including memory tests that required them to recall several images. The children and their parents also answered questions about the kids' feelings about their genders and how they typically play and express themselves. "It's not anything clinical," Dhamala noted. "It's just an aspect of behavior that represents your gender."

These answers were used to generate "scores" for each child that the AI algorithm could use as data points.

The algorithm ultimately revealed two largely distinct brain networks tied to sex and gender. The brain differences most strongly tied to sex were found in networks responsible for processing visual stimuli and physical sensations, controlling movement, making decisions and regulating emotions. Differences tied to gender were more widely dispersed, involving connections within and between many areas in the cortex.

After pinpointing these networks, the researchers trained their AI algorithms to "predict" a child's sex or gender based on brain activity. They accurately determined most children's sexes, similar to the results of Lui's study. Gender proved trickier: With the children's questionnaire answers, the AI couldn't predict where they landed on a continuum of gender, whereas with the parents' answers, its predictive power exceeded chance but was still "much lower" than the predictions for sex, Dhamala said.

Nonetheless, the study highlighted an understudied idea: that gender sculpts the brain in ways that are distinct from sex, she said.

Interestingly, some tentative lines can be drawn between Lui's and Dhamala's AI-powered studies. They can't be directly compared, as the two studies used different types of analyses and focused on different features of the brain. But many of the physical white matter tracts flagged in the former study correspond with functional networks highlighted in the latter, Dhamala told Live Science.

As an example, the cingulum — a white-matter tract that encircles the corpus callosum — seemed key for making predictions in Lui's study. It also links together various networks flagged in Dhamala's study, including circuits involved in emotional processing. That hints that sex differences exist in both the physical anatomy of these networks and in their activation patterns, Dhamala said.

The future of the sex-difference field

Scientists have made some progress at teasing out sex differences in the brain, but to truly understand these distinctions, researchers will need to do more animal studies to allow for more experimental control, according to a 2020 paper co-authored by Raznahan.

Various studies in lab rats have already revealed differences in how males and females form connections between neurons, and how each sex processes fearful memories, for example.

Related: 'Let's just study males and keep it simple': How excluding female animals from research held neuroscience back, and could do so again

In humans, scientists can collect more brain data right at the time of birth, to pinpoint baseline differences that might exist before a child encounters any cultural influences, and then track the child over time, Raznahan and colleagues added.

Another option is to study human genes that are unique to either the X or Y chromosome. By looking at people with extra or missing sex chromosomes, for example, scientists have started to unravel how these genes either inflate or shrink brain structures, contributing to sex differences in size. Chromosomes may also raise or lower the risk of disorders — for instance, carrying an extra Y raises the likelihood that a person has autism, whereas an extra X does not. That may help to explain why males, who usually carry one X and one Y, have higher autism rates than females, who typically have two Xs.

Right now, the fate of such research is uncertain in the U.S.

Prompted by executive orders from the new presidential administration, the National Science Foundation has been combing through active research projects to see if they include words that might violate said orders, such as "woman," "female" and "gender," and the National Institutes of Health appeared to archive a long-standing policy requiring both male and female lab animals in studies.

"There's just a lot of uncertainty," Dhamala told Live Science. If the worst case scenario comes to pass, "removing that gender component, or making it harder to study sex differences, is going to push us backward rather than forward."

But if the field survives, future work could incorporate gender the way the ABCD study did, using questionnaires to generate composite scores, Dhamala said. As a start, scientists could at least ask study participants what gender they identify as, she added. Other experts agree.

By adopting these strategies, scientists could dramatically advance this research field that dates back to Aristotle. Their efforts could lend new talking points to the endless debate of nature versus nature. They could uncover meaningful sex differences that pave the way to better treatments for depression, Alzheimer's and more. Or they could highlight the ways members of the "opposite sex" are actually more alike than they are different.

Gender reveal parties are best known as celebrations involving pink and blue, cake and confetti, and the occasional wildfire. Along with being social media hits, gender reveals are a testament to how society is squeezing children into one of two predetermined gender boxes before they are even born.

These parties are often based on the 18- to 20-week ultrasound, otherwise known as the anatomy scan. This is the point during fetal development when the genitals are typically observed and the word "boy" or "girl" can be secretly written on a piece of paper and placed into an envelope for the planned reveal.

Now there is a new player in the gender reveal game: genetic screening.

Advancements in genetic research have led to the development of a simple blood test called cell-free DNA prenatal screening that screens for whether a baby has extra or missing pieces of genetic information — chromosomes — as early as 10 weeks into pregnancy. Included in this test are the sex chromosomes, otherwise known as X and Y, that play a role in the development and function of the body.

This blood test is more informally called noninvasive prenatal testing, or NIPT. Many people refer to it as "the gender test." But this blood test cannot determine gender.

As genetic counselors and clinical researchers working to improve genetic services for gender-diverse and intersex people, we emphasize the significance of using precise and accurate language when discussing genetic testing. This is critical for providing affirming counseling to any patient seeking pregnancy-related genetic testing and resisting the erasure of transgender and intersex people in health care.

Distinguishing sex and sex chromosomes

Sex and gender are often used interchangeably, but they represent entirely different concepts.

Typically when people think of sex, they think of the categories female or male. Most commonly, sex is assigned by health care providers at birth based on the genitals they observe on the newborn. Sex may also be assigned based on the X and Y chromosomes found on a genetic test. Commonly, people with XX chromosomes are assigned female at birth, and people with XY chromosomes are assigned male. Since cell-free DNA, or cfDNA, prenatal screening can report on sex chromosomes months before birth, babies are receiving sex assignments much sooner than previously possible.

While cfDNA prenatal screening can offer insights into what sex chromosomes an infant may have, sex determination is much more complicated than just X’s and Y’s.

For one, sex chromosomes don’t exactly determine someone’s sex. Other chromosomes, hormone receptors, neural pathways, reproductive organs and environmental factors contribute to sex determination as well, not unlike an orchestra with its ensemble of instruments. Each cello, flute, tympani and violin plays a crucial role in the performance of the final musical score. There is no single instrument that defines the entirety of the symphony.

RELATED: Fetal testosterone may program boys' behavior

Intersex people, or those with variations in sex characteristics that deviate from societal norms of binary sex, exemplify the complexities of sex. These variations can manifest in various ways beyond X and Y chromosomes, such as differences in hormone levels, genitalia or secondary sexual characteristics.

The oversimplification of sex based on societal norms has led many to believe that there are only two discrete sexes. The binary framework of sex excludes intersex people and perpetuates their erasure and mistreatment within both health care and society at large.

For instance, many intersex individuals face unnecessary surgeries, such as nonconsensual genital procedures, to conform to binary norms, violating their bodily autonomy.

Where gender comes in

While sex typically describes someone’s anatomical characteristics, gender is an umbrella term that encompasses the way someone views and presents themselves to the world. Countless aspects influence how someone defines their own gender and how the world views their gender, including clothing, haircuts and voice tone. Similar to how Western cultures have historically confined sex to two buckets, it has also created two gender categories: man and woman.

Gender is not dependent on anatomical parts or chromosomes. People are not math equations, and having certain combinations of biological parts does not equal someone’s gender. For example, some people may be transgender, meaning their assigned sex is not congruent with their socially or self-defined gender. Nonbinary people do not identify exclusively with either of the two genders in the binary, regardless of their assigned sex.

Just like sex diversity, gender diversity is not rare. A 2022 Pew Research Center analysis found that approximately 5% of adults in the U.S. under the age of 30 are transgender or nonbinary.

These estimates will likely increase as societal awareness and acceptance of gender-diverse individuals increases. Anti-transgender legislation often oversimplifies gender as strictly binary, conflating it solely with sex assigned at birth.

Intersex and gender-diverse people show that sex and gender are both multidimensional. Gender is not solely determined by biology, and it is erroneous to define someone’s gender by their sex, much less by their sex chromosomes.

Challenging sex and gender norms

The idea that biology plays the largest role in determining who an individual is, or bioessentialism, has governed misconceptions about sex and gender for many years. This concept is used to confine people to buckets and limit their self-determination.

For instance, societal norms dictate that women should be nurturing and gentle, while men are expected to be protective and assertive. Such rigid gender roles, often enforced through the lens of biology, serve to uphold notions of evolutionary destiny and a purported natural order.

Marketing strategies for children’s toys often adhere strictly to gender roles, steering girls toward dolls and domestic play sets while steering boys toward action figures and construction sets.

Educational systems often reinforce gender norms by directing girls toward subjects such as literature and arts while steering boys toward science and mathematics. This perpetuates the notion that certain traits and interests are inherently linked to one’s sex and gender, thereby reinforcing societal norms and sustaining inequality.

Upholding binary constructs of sex and gender does not allow for individuality and gender fluidity. Categorizing people from the time their chromosomes are analyzed or the moment their genitals are observed at birth restricts their autonomy and authenticity. These simple assumptions set expectations that can be harmful.

Letting children define themselves

If you’re a parent offered cfDNA prenatal screening during pregnancy, remember that it is commenting only on one instrument in the orchestra of sex. It cannot examine all of the other factors that determine sex as a whole. And it most certainly cannot determine gender, which is an entirely different concert.

In recent years, Jenna Karvunidis, the mother considered the inventor of gender reveal parties, shared her regrets for starting the trend and noted that her views on sex and gender have shifted. In a 2019 Facebook post, Karvunidis wrote, "PLOT TWIST. The world’s first gender reveal party baby is a girl who wears suits!" She had also gone on to say, "Celebrate the baby … Let’s just have a cake."

When the envelope is opened, the balloons are popped and the crafty cake is cut, consider how these practices perpetuate social confinements and a gendered destiny for your little bundle of joy. Perhaps opt simply for a celebration that leaves space for your child to one day define who they are.

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

Roughly 2,500-year-old DNA has revealed the first ancient person on record with Turner syndrome, a genetic condition in which a person has just a single X chromosome rather than two, a new study finds.

The individual, who died when they were 18 to 22 years old, likely hadn't gone through puberty, an analysis of the bones revealed. A further investigation of the remains revealed that the individual had mosaic Turner syndrome, as some cells had just one X chromosome while others had two.

The research looked at historical DNA gathered in the Thousand Ancient British Genomes project — a database of DNA being collected from skeletons in the U.K. The team identified a total of six people with sex chromosomal conditions, according to a study published Jan. 11 in the journal Communications Biology.

The researchers made the discoveries after developing a computational method to find atypical numbers of chromosomes in DNA from skeletons.

Related: Europeans' ancient ancestors passed down genes tied to multiple sclerosis, Alzheimer's risk

The individual with Turner syndrome, who died in the early Iron Age (750 to 400 B.C.) likely had a partially missing second X chromosome. This condition can often lead to symptoms and characteristics such as shorter-than-average height, cardiac defects and small or absent ovaries, leading to fertility issues.

Of the other five people with aneuploidies, or genetic disorders in which a person doesn't have 46 chromosomes, three individuals showed signs of Klinefelter syndrome — a genetic condition in which a person has an XXY set of sex chromosomes. Of these three individuals, one died in the Iron Age (circa 750 B.C. to A.D. 43), one in the high Middle Ages (around A.D. 1050 to 1290) and one in the early 19th century. Klinefelter syndrome often stunts the growth of a person's testicles, leading to lower testosterone levels, lower muscle mass, less body hair and larger breast tissue than typical XY individuals.

The three skeletons identified with this condition were buried in ways typical for their times, according to the study, showing that "their burials did not reveal any differences in how they were perceived by their contemporaries," the researchers wrote.

Another male individual from the early medieval period (eighth century) had an extra Y sex chromosome, known as XYY syndrome. Most people who have XYY chromosomes have no physical features that are different than people with XY chromosomes, other than often being taller than average.

The researchers also identified a male infant from Iron Age Britain who had Down syndrome. This condition can result in neurodevelopmental problems, and identifying skeletons with the syndrome "can provide insights into care within ancient societies, as well as how people with these conditions, which have characteristic physical manifestations, were perceived by their peers," the researchers wrote in the study.

Although the number of people with chromosomal differences revealed in this study is small, the researchers' new method gives them the opportunity to observe genetic diversity to "provide another layer of information that can contribute to a more detailed reconstruction of the human past," they wrote in the study.

In particular, making it easier to study variations in sex chromosomes in ancient DNA can help move the field of skeletal analysis beyond binary sex estimations and into a more complex understanding of social gender.

"It is difficult to know an ancient individual's conception of their own gender identity, and gender norms in the past may not align with those of the present day," the researchers wrote in their study. "It is possible that an elevated proportion would have been seen to transgress gender boundaries."

Roses are red, violets are blue, and in between are a million other hues. But which one of these colors is, statistically speaking, the most popular around the world?

It turns out that humanity's favorite hue isn't constant. A 2015 survey by YouGov found that blue was the most popular color worldwide. Meanwhile, in 2017, a survey of 30,000 people across 100 countries found deep teal to be the most popular color, The Independent reported. The answer seems to vary with the year, survey method and population sampled.

And color preferences are highly influenced by culture. For instance, a 2019 study in the journal Perception compared the favorite hues of people in Polish, Papuan and Hadza cultures. (The Hadza are a hunter-gatherer group that lives in Tanzania.) Preferred colors diverged widely among these cultures.

Related: Why is the color blue so rare in nature?

Even within the same culture, life experiences and socialization may shape color preference. For instance, in modern Western culture, blue is traditionally associated with boys, while pink is considered a "girl's color." And, unsurprisingly, a 2013 study in the journal Archives of Sexual Behavior that surveyed 749 American parents found that men tended to prefer blue while women tended to prefer red, purple and pink. This gender divide was heightened in families with only sons; in other words, men who had only sons more strongly preferred blue than did men who had girls. Meanwhile, for the Hadza, whose society is fairly egalitarian, color preferences were practically identical between men and women, the Perception study found. 

The perception and categorization of colors, however, does seem to be fairly universal. 

In the late 1970s, researchers with the World Color Survey undertook an incredibly broad survey of the color terms in 110 unwritten languages across the world. The objective was to test the hypothesis, articulated by American linguist Benjamin Lee Whorf in MIT Technology Review in 1940, that "we dissect nature along lines laid down by our native language. Language is not simply a reporting device for experience, but a defining framework for it." 

In other words, language shapes the perception of reality.

But that's not what the World Color Survey found. Instead, the survey found that across cultures, people tended to name hues the same way. For example, if you show people different hues that in English are clustered close to "blue," chances are that in Tagalog, Turkish or Tajik, those same hues will all be described by a word that roughly translates to "blue," too. And across cultures, speakers tend to place the boundary between foundational colors — such as red, blue, yellow and green — in roughly the same place. So the point where blue bleeds into green, or yellow into orange, was demarcated in the same places across cultures. 

Originally published on Live Science on July 31, 2012, and rewritten on July 25, 2022.

Transgender is an umbrella term that describes people whose gender identity or expression does not match the sex they were assigned at birth. For example, a transgender person may identify as a woman despite having been born with male genitalia.

About 1.4 million adults in the United States identify as transgender, according to 2016 research by the Williams Institute at the University of California, Los Angeles. Broken down on a state level, that research found that 0.8% of adults in California, Georgia, Hawaii and New Mexico identify as transgender, compared with 0.3% of adults in Iowa, Montana, North Dakota South Dakota and Wyoming identify as such.

What is transgender?

Being transgender means different things to different people, according to the National Center for Transgender Equality (NCTE). "There's no one way to be transgender, and no one way for transgender people to look or feel about themselves," the organization says on its website.

A person's internal sense of being male, female or something else is their gender identity. For cisgender, or non-transgender people, their gender identity matches their sex at birth. For transgender people, the two do not match. 

Sometimes, a person's gender identity doesn't fit neatly into two choices. People who see themselves as being both male and female, neither male nor female or as falling completely outside these categories may identify as genderqueer, according to the Human Rights Campaign (HRC), an LGBTQ advocacy organization. (LGBTQ refers to the community of lesbian, gay, bisexual, transgender and queer or questioning individuals.)

How a person communicates their gender identity — through dress, behavior, voice or body characteristics — is their gender expression. A person's gender expression may or may not line up with society's expectations of masculinity or femininity, according to the HRC. The term "gender non-conforming" refers to people whose gender expression is different from conventional expectations of masculinity or femininity. However, not all gender-non-conforming people identify as transgender, and not all transgender people identify as gender non-conforming.

The public's understanding of gender identity and expression is evolving as more transgender people share their stories, according to the HRC.

The transgender flag

The transgender flag was designed in 1999 by Monica Helms, an openly transgender American woman and Navy veteran, according to nonprofit organization Point of Pride. The light blue and pink tones represent traditional colors for baby boys and girls, while the white horizontal line represents "those who are intersex, transitioning or consider themselves having a neutral or undefined gender."

According to Point of Pride, the flag is designed to be symmetrical so it appears the same whichever way up it is flown. The original flag created by Helms, and first displayed at a pride parade in Phoenix, Arizona, in 2000, is now held at the Smithsonian National Museum of American History.

Sex versus gender

Sex and gender are two different concepts. A person's sex refers to his or her biological status as either male or female. The determination of a person's sex depends primarily on various physical characteristics, including chromosomes, reproductive anatomy and sex hormones, according to the American Psychological Association (APA). 

Gender, on the other hand, is a societal construct that deals with the expected behaviors, roles and activities typically associated with the different sexes, the APA said. Gender roles, which vary across cultures, influence how people act and feel about themselves.

Sexual orientation is different from gender identity. Sexual orientation is a person's physical, emotional or romantic attraction to another person, while gender identity is about one's own sense of self, according to GLAAD, an anti-discrimination organization. Transgender people may be straight, lesbian, gay or bisexual. For example, a person born with male genitalia may transition to being female but may be attracted to females. In this case, the person may identify as lesbian even though she was born with male genitalia.

Making the transition

Trying to change a person's gender identity is no more successful than trying to change a person's sexual orientation, GLAAD said. In other words, it can't be changed. Some people may take steps to better align their sex with their gender using hormones and surgery. HRC points out, however, that many transgender people cannot afford medical treatment or have no desire to pursue surgeries.

"So-called 'gender reassignment surgery' (more commonly called 'gender-affirmation surgery' by both medical professionals and transgender individuals) usually references transgender genital surgery," said Dr. Joshua Safer, medical director of the Center for Transgender Medicine and Surgery at Boston Medical Center (BMC), who is also in the BMC Department of Endocrinology. "There are also chest-reconstruction surgeries and facial feminization surgeries, among other options."

Genital surgery is typically reserved for transgender individuals over the age of 18 who have been treated with hormones, if that is what is medically indicated, and who have lived for at least a year in the gender roles that match their gender identities, Safer said. Candidates for surgery are reviewed by a medical team that considers mental health and physical health in determining the best treatment strategy, potentially including surgery, for each person.

Related: How gender reassignment surgery works

Altering the voice so that it better matches gender identity can also be important to those transitioning. "Here, we envision a world where a transgender person feels no need to change their voice or speech — that is, they would live in a world where people accept and respect them as whatever gender they claim, regardless of how their voice sounds," said Dr. Leah Helou, a speech pathologist who leads the University of Pittsburgh Voice Center's transgender voice and communication services. 

"However, in the absence of such radical and global acceptance, many trans individuals feel that their communication style is a top priority for making their external self congruent with their inner self," Helou said. "Our goal is to serve and support those people, while advocating for broader acceptance of the transgender population."

Names and pronouns

After transitioning, transgender people often change their names — either to one that matches their gender or to something neutral. A critical step in transitioning is changing legal documents, including driver's licenses, Social Security cards, passports and credit cards. They often have to go to court to order the changes to be made — an expensive, time-consuming task, according to the NCTE.

It is considered rude to call people who have transitioned by their former name (called "dead-naming"), and it is appropriate to respectfully ask them their name and which pronouns they prefer, according to the HRC.

Most transgender people prefer to be identified with the pronoun that corresponds to the gender with which they identify, according to the HRC. A transgender woman should be called "she" or "her," if that's what she prefers. Some transgender people don't believe in binary gender appellations and prefer "they" or a non-gendered pronoun.

Discrimination

Being transgender is not a mental disorder. It cannot be "cured" with treatment. Transgender people may experience a persistent disconnect between their assigned sex and their internal sense of who they are, according to the HRC. Medical professionals refer to this disconnect as gender dysphoria because it can cause pain and distress in the lives of transgender people.

In 2012 The American Psychiatric Association announced that a new version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) would replace the term "gender identity disorder" with the more neutral term "gender dysphoria." This was followed in 2019 by the World Health Organization removing the term "gender identity disorder" from its list of mental illnesses, CBS reported. 

Research has shown that transgender people are at high risk of experiencing prejudice and mental-health problems. The 2015 National Transgender Discrimination Survey found that 60% of health care providers refuse treatment to transgender people. Additionally, the research found that 64% to 65% of the transgender people surveyed suffered physical or sexual violence at work, and 63% to 78% suffered physical or sexual violence at school. 

In the most recent iteration of this survey, taken in 2015, results revealed that even children are at risk: Those in grades K through 12 who had come out as transgender reported being verbally harassed (54%), physically attacked (24%) and sexually assaulted (13%) because of their sexual identity.

Transgender people often face discrimination even when using the bathroom. In a 2016 poll of Americans by CBS and The New York Times, 46% of respondents said those who are transgender should use the bathrooms assigned to their birth genders, while 41% said such individuals should be able use the bathroom that matches their identities. In May 2016, the U.S. Education and Justice departments stepped in to advise school districts to permit transgender students to use bathrooms and locker rooms that matched the students' gender identities. In response, several states joined in a lawsuit, stating that the federal government had overreached its authority.

Because of discrimination and other factors, the suicide rate among transgender people is high. The Suicide Prevention Resource Center reports that more than 83% of transgender people had thought about suicide and 54% had attempted it. (The National Suicide Prevention Lifeline is 1-800-273-8255.)

Help for parents

Parents who think their children may be transgender should seek the assistance of experts. "Determining if children are transgender can be a challenge and should be done with careful evaluation from a knowledgeable multidisciplinary team," Safer said.  

It is important to note that many children question their gender identities without being transgender. Safer advised parents to be respectful of the child's feelings and recognize that there will be no actual medical intervention until the child begins puberty. Even then, initial medical treatments are reversible, he said.

Related: How parents and doctors can support transgender children

Transgender history

Though transgender people have existed for hundreds and even thousands of years according to an article by the HRC, the transgender movement for social change has existed for less than a hundred years. According to Susan Stryker, a visiting professor at Yale University, laws specifically targeting transgender people began to emerge in the 19th century. "In the 1850s, a number of U.S. cities began passing municipal ordinances that made it illegal for a man or woman to appear in public "in a dress not belonging to his or her sex,"' she wrote in her book "Transgender History" (Da Capo Press, 2009).

In the early 20th century, gender reassignment, or affirmation, surgery was only being carried out in a few specialist medical centers around the world. One of the largest, in Germany, was targeted by the Nazis, according to Elliot Evans, author of "Queer Permeability" (Routledge, 2020). "Magnus Hirschfeld’s pioneering Institut für Sexualwissenschaft [Institute of Sexology, or Sexual Science] in Berlin, provided treatment for Lili Elbe (whose story was made famous by the 2015 film "The Danish Girl") and Dora Richter," Evans wrote in an article for All About History magazine. "It was all but destroyed after Hitler came to power in 1933, its archives and library publicly burned. The Institute only re-emerged – this time in Frankfurt – in 1973." 

Transgender healthcare did not fully emerge until the second half of the 20th century, though it was still very limited and in many countries gender affirmation surgery remained illegal. "In the US, the Stanford Gender Dysphoria Program in Palo Alto, California, associated with the pioneering doctor of transgender healthcare, Harry Benjamin, would not be founded until 1968," Evans wrote. "Some medical assistance for trans individuals was available in Europe: in Sweden, and in Denmark’s Copenhagen University Hospital, which provided surgical interventions for the American trans woman Christine Jorgensen in the early 1950s, after she had obtained special legal permission from the Danish Minister of Justice." 

Additional resources

• National Center for Transgender Equality
• The Journal of Homosexuality: Attempted suicide among transgender persons: The influence of gender-based discrimination and victimization
• Human Rights Campaign: Transgender FAQ

Why is there a persistent wage gap between men and women? Turns out, religion may play a big role in the disparity. 

New research finds that the wage gap is 8 percentage points wider in the five most religious states than in the five most secular, with women making 18% less than men in the least religious states and 26% less in the most religious. What's more, the gender gap is projected to vanish in 28 years in the most secular states, compared with a stunning 109 years in the most religious. 

"If they're in a religious community, our children are not going to know a world in which they're paid equitably," said Traci Sitzmann, an associate professor of management at the University of Colorado, Denver. "It's a little bit scary." 

Related: 20 amazing women in science and math

Religion and wages

Sitzmann and her colleague Elizabeth Campbell, an assistant professor of work and organizations at the University of Minnesota, were interested in exploring the impacts of religiosity on workforce issues. They started with a global view. Using data from 140 countries, they compared the likelihood of citizens answering "yes" to the question, "Is religion important in your daily life?" with the gender wage gap in those countries as of 2013, the most recent global data available. They found a striking association: The more religious a country, the greater the wage gap. In nations where more than 95% or more people said religion was important in their daily lives, such as Pakistan and the Philippines, women earned around 46% as much as men. 

In countries where fewer than 20% of people said religion was important to them in daily life, such as Sweden and Estonia, women averaged around 75% of men's wages. The United States had moderately high religiosity and women in the U.S. earned 66 cents for every dollar men earned, Sitzmann told Live Science. 

The effect held true for all major world religions, Sitzmann said. It didn't matter if most believers in a country were Jewish, Christian, Muslim, Buddhist, Hindu or adherants to a folk religion. The wage gap was still greater in countries where religion played a major role in daily life. 

Related: 7 sexist ideas that once plagued science

The researchers then turned to Gallup survey data on religious service attendance and the importance of religion in daily life in the 50 U.S. states. In the U.S. data, the researchers looked only at full-time wages so as not to skew the results due to women working fewer hours.

They again found that the more religious the state, the greater the wage gap. (Mississippi, Alabama, Utah, South Dakota and South Carolina were the most religious states; Vermont, Maine, Massachusetts, Rhode Island and Nevada were the least.) The researchers found that religiosity explained 17% of the variability in the gender wage gap between states. To ensure that the wider economy or levels of conservatism weren’t responsible for the difference, the researchers then looked at year-over-year data between 2008 and 2018 and found that the association between religion and wages still held. The gender gap is shrinking over time in the U.S., they found, but it is shrinking faster in secular states compared with religious ones. At current rates, it will take more than a century for the gap to close in the most religious states.

According to the workplace data analysis company PayScale, women make 81 cents for every dollar men make as of 2020. This analysis compares median salaries for men and women, and does not control for factors like seniority, years experience and education, all of which can be impacted by gender discrimination and gender role expectations.

The pathway to a wage gap

Sitzmann and Campbell found three reasons for this difference in wages between secular and religious regions. The more religious a country or state, the more that society differentiated the roles of men and women. In other words, women in more religious societies are expected to put family first. The researchers measured this by looking at how many babies women have, how many women work at all, access to abortion and family-friendly work policies. In more religious societies, women have more children, participate less in the workforce, have less access both to abortion and to policies that help balance work with family. 

Religious societies are also more likely to sexually objectify women, the researchers found. They measured this by looking at regional Google Trends for the search terms "pornography" and "rape." Both were correlated with religiosity, and both were correlated with the gender wage gap. 

Related: 7 sexist ideas that once plagued science

Finally, religious societies are also less likely to promote or accept women in leadership positions. "We've got the Pope saying, 'the door is closed, women are not allowed to be leaders in the church,'" Sitzmann said, referring to Pope Francis' 2013 statement on female priests in the Catholic Church. "That sets the stage for a very strong norm." 

She and Campbell found that in more religious societies, women have less representation in politics and in organizational leadership. They also have lower educational attainment and less legal equality. 

Closing the gap

Finally, the researchers conducted experiments to confirm that it was indeed religion, and not some closely related concept like conservatism, that explained the results. They set up an online game in which 91 participants, about half women and half men, acted as managers who had to allocate wages to employees based on performance reviews. All of the participants saw the same performance reviews, but in some cases the employee was named Patricia Anderson and in others was called Michael Taylor. 

Before seeing the performance reviews, some participants saw a description of the mock company they were working for that described it as faith-based. Others saw a description that focused on the company's dedication to communication and community. 

Those who were primed to believe they were working for a religious company allocated 3% more to the male employee compared with the female employee. In contrast, those who thought the organization was secular allocated 6% more to the female employee.

But there was a way to reverse the inequality. When the researchers told people in the mock religious company that one of the company values was that women needed to be involved, and that the company had a strict anti-sexual-harassment policy, it wiped out the gender wage gap, according to their research paper published Oct. 27 in the Academy of Management Journal.

This was a heartening result, Sitzmann said, because it suggests that simply being aware of expectations for gender equality will help make people behave more equitably. 

The major world religions all developed after humans had settled into agricultural societies in which men and women were typically prescribed different roles, said Stephanie Coontz, a historian at The Evergreen State College in Washington and the director of research and public education for the Council on Contemporary Families. Their edicts thus "tend to support a division of labor and a division of authority that put women as second-class," said Coontz, who was not involved in the new research. 

But there is a lot of room for interpretation in the major world religions' texts, Coontz added, and many passages affirm a more modern view of equality. 

"It's certainly not determinative," she said. "Many, many people who are religious have taken some of these things with a grain of salt."

National policy could help enshrine equality as a societal value, Sitzmann said. Two years ago, Iceland instituted a policy that requires companies to make their wage data available for independent review. Any company not paying men and women the same wages for equal work is fined. (The policy is currently being implemented in stages over four years, starting with the largest companies.) 

"In the end," Sitzmann said, "you want your wages to be correlated with your performance, not your gender." 

Originally published on Live Science.

The sex we're assigned at birth depends largely on a genetic flip of the coin: X or Y? Two X chromosomes and you (almost always) develop ovaries. An X and a Y chromosome? Testes. These packages of genetic material don't just differ in terms of the body parts they give us. With 45 genes (in comparison to around 1,000 on the X), the Y chromosome is puny. And research suggests it has shrunk over time — a proposition that some have, in turns, glumly or gleefully interpreted as predicting the demise of men.

So is the Y chromosome really dying out? And what might that mean for men?

To begin to answer these questions, we have to go back in time. "Our sex chromosomes weren't always X and Y," said Melissa Wilson, an evolutionary biologist at Arizona State University. "What determined maleness or femaleness was not specifically linked to them." 

Related: Why do men have nipples?

When the very first mammals evolved between 100 and 200 million years ago, they didn't have any sex chromosomes at all. Instead, the X and Y were just like any other set of chromosomes — identical in size with corresponding structures, Wilson said.

It's important to note that animals don't need sex chromosomes. That was true then, and it's still true now, said Jennifer Graves, a geneticist at La Trobe University in Melbourne, Australia. All of our chromosomes are a cocktail of sex-related and non-sex-related genes. The only special feature of the Y chromosome is one gene, SRY, which acts as an on-off switch for the development of testes, Graves added. In the case of alligators and turtles, an on-off switch isn't even necessary — the temperature in which embryos develop determines their sex. Our mammalian ancestors likely shared this characteristic, Graves wrote in a 2006 review on the subject, published in the journal Cell. But at some point, a plain old, non-sex chromosome in one of these ancestors developed a gene with an on-off switch like this. And that was it: you suddenly needed a Y to develop male reproductive parts.

But as soon as the Y chromosome existed, it was primed to shrink. Over time, genes develop mutations, many of which are harmful, Wilson said. Chromosomes can avoid passing on these mutations by recombining with one another. During meiosis, when our bodies produce sperm and eggs, paternal and maternal chromosomes randomly mix and match their arms. This genetic dance breaks up variants of genes — harmful and beneficial alike — and makes it more likely that only functional copies will get passed on. All the chromosomes do this: chromosome 1 from mom swaps arms with chromosome 1 from dad, and so on. The Y, however, does not have a swapping companion. Although X chromosomes can recombine with one another, Y chromosomes and X chromosomes aren't similar enough to recombine. And because you rarely have two Y chromosomes in an individual, Y can't recombine with itself. 

"If a bad mutation occurs, usually you'd be able to swap with your partner. But the Y can't do that," Wilson said. So Y chromosomes accumulated harmful mutations; over time, those mutations were weeded out by natural selection until the Y got smaller and smaller. 

Graves's research suggests that 166 million years ago, the Y chromosome had 1,669 genes — "same as the X-chromosome" at that time, she said. "So it doesn't take a great brain to realize that if the rate of loss is uniform — 10 genes per million years — and we've only got 45 left, the whole Y will disappear in 4.5 million years." 

Uniform is the key word here. More recent research suggests that the rate of degradation has slowed over time. In a 2005 study published in the journal Nature, researchers compared the human Y chromosome with that of a chimpanzee. Then in 2012, the same team of researchers sequenced the Y chromosome of a rhesus monkey, again publishing the results in Nature. The researchers found that the human Y chromosome has lost only one gene since humans and rhesus monkeys diverged evolutionarily 25 million years ago. It hasn't lost any genes since the divergence of chimpanzees 6 million years ago. These results suggest that decay has not occurred in the linear fashion that Graves originally suggested, in which 10 genes are lost per million years.

Related: Why do women have orgasms?

Loss of the Y chromosome isn't off the table — it's happened to other species, Graves pointed out. Two species of underground rodents called mole voles have independently lost their Y chromosomes. So have three endangered species of spiny rats living on several small islands in Japan.

But as those species demonstrate, the loss of the Y chromosome doesn't doom survival; both spiny rats and mole voles still have males and females. "People think that sex is sort of a very determined thing," said Rasmus Nielsen, a geneticist at the University of California, Berkeley, "That if you have a Y chromosome, then you're a man, or you don't have [a] Y chromosome, then you're female. But it doesn't work like that." 

In fact, 95% of genes that are expressed differently between males and females don't actually live on the X and Y chromosomes, Wilson said. For instance, ESR1, a gene that encodes for estrogen receptors, is found on chromosome 6. These receptors are vital for female growth and sexual development. 

"Losing the Y chromosome doesn't mean losing the male," Nielsen added. Instead, the loss of the Y chromosome would likely mean that another gene would take over the job as the main determinant of sex — the on-off switch, Graves said. "There are heaps of genes out there that will do a perfectly good job." 

But how likely is that to happen? "It's possible," Wilson said, "but not in our lifetime."

Originally published on Live Science.

Fathers forced to work from home by the coronavirus pandemic take on more childcare than their usual, new research finds. But moms are more often stuck juggling kids and work at the same time. Moms are also more stressed than men about new work-at-home arrangements. 

The closure of schools and many childcare centers has put working parents in a bind, according to the new briefing, which was written by Yale sociologists Thomas Lyttelton and Emma Zang and Kelly Musick, the chair of policy analysis and management at Cornell University, for the Council on Contemporary Families (CCF), a nonprofit research organization. In April and May of 2020, 55% of employed parents were working from home, the researchers wrote. During this time, most public schools were closed. 

Lyttelton and Zang used data from the American Time Use Survey (ATUS) collected between 2003 and 2018 to measure how telecommuting affected the division of labor pre-pandemic. This survey is run by the U.S. Bureau of Labor Statistics and asks participants to log their daily time spent doing activities such as paid work, house work and childcare. Unfortunately, the call center that runs the ATUS surveys shut down due to COVID-19 between March 19 and May 11, meaning that data from those dates were missing. To measure at least some changes during the pandemic, the researchers turned to the COVID Impact Survey, run by the Data Foundation, a nonprofit think tank that seeks to use data to improve policy, which gathered data on time use in April and May.

Related: Coronavirus outbreak: Live updates

The effects of telecommuting 

The pre-pandemic data showed that a parent who telecommutes typically takes on more of the domestic load. Telecommuting dads, in particular, take on extra childcare on work-from-home days: 67 more minutes than non-work-from-home days, to be exact. This increase actually closed the normally-seen gender gap in which women spend more time on childcare than men. When women telecommuted pre-pandemic, they added 47 minutes of childcare to their day, compared to the days when they worked away from home. 

But dads don't do any extra housework when they telecommute, while telecommuting moms take on 49 more minutes of housework. Pre-pandemic, telecommuting dads also seemed to maintain better boundaries between work and childcare while working at home. Men reported that children were with them for an average of 21 minutes a day while they worked from home, whereas women reported that they were working with their children present for 54 minutes a day. 

Many women feel pressure to keep up housework and attend to their children every time the kids interrupt, said Stephanie Coontz, a sociologist at The Evergreen State University in Washington and the director of research at CCF. "This is a form of work-family conflict people often ignore when they tout the advantages of working from home, and as this report shows, it's a source of gender inequality at home and at work."

Related: Doting dads: 6 of history's finest fathers

Pandemic work-from-home

Given the shutdown of ATUS data collection, the researchers couldn’t directly compare these pre-pandemic results to the situation during the pandemic. The COVID-19 Impact Survey did show, however, that all parents who worked from home during the pandemic were more depressed than those still reporting to a workplace. Mothers were hit particularly hard. Moms telecommuting during the pandemic reported more anxiety, loneliness and depression than telecommuting dads. Moms who did their work outside the home reported no such increase, and telecommuting dads actually felt less anxiety than dads who were reporting to a workplace.

Notably, the data showed that the worst position to be in was to be unemployed: Unemployed mothers and fathers were consistently more anxious, depressed, lonely and hopeless than parents who still had jobs. 

In May, a  previous CCF survey of 1,060 parents in different-sex couples found that both men and women agreed that men were carrying more of the domestic load during the COVID-19 pandemic compared with what they did pre-pandemic. Pre-pandemic, 26% of couples reported sharing housework relatively equally, a number that rose to 41% in April. Forty-one percent of couples pre-pandemic reported sharing the care of young children equally, which rose to 52% after the pandemic began. That survey also found that stay-at-home orders had lessened some of the domestic load by eliminating tasks like hauling children to extracurricular activities or planning their daily schedules. 

However, the picture gets murkier when zooming in specifically on homeschooling children. An April survey commissioned by The New York Times found that 80% of women said they were doing most of the schooling of their children, compared to 45% of men. Clearly, given that these numbers add up to more than 100%, a significant number of couples disagree about who is doing the most. Only 3% of women agreed that their male partners were doing the most when it came to teaching kids at home. 

Editor's note: This article was updated to correct the spelling of Emma Zang's name.

Originally published on Live Science.

One last night on the town as an unmarried person — that's how we've come to characterize bachelor and bachelorette parties (or hen and stag-dos in the U.K.; Jack and Jill parties if you're in Australia). Marriage may not be the end of fun, but celebrating the end of an era has become an integral part of pre-wedding festivities in the Western world. 

But what did these parties look like hundreds of years ago? And how did they come to be associated with drinking, late nights and debauchery?

The bachelor/bachelorette party as we know it is a modern phenomenon. The first reference to a bachelor party was recorded in 1922, Time reported, and it wasn't until much later that heavy drinking and adult entertainment became the norm for these parties. But at their core, bachelor and bachelorette parties are rites of passage, said Thomas Thurnell-Read, a sociologist at Loughborough University in the United Kingdom who studies pre-wedding rituals. "You've got a young person going from one status to another," he said. And people have been holding gendered rituals and celebrations marking the end of singledom since antiquity. 

Related: What if someone objects at your wedding?

For thousands of years, pre-wedding rituals emphasized the cleanliness or purity of the bride. Women in ancient Greece spent the day prior to marriage — known as proaulia — making offerings and sacrifices to gods, especially Artemis, the goddess of chastity and childbirth, wrote historian Emily Brand for BBC History Magazine. In 17th-century Sweden, the bride celebrated mökvällarr ("virgin nights") by taking a bath with her virgin friends, Eva Knuts wrote in the book "Masks and Mumming in the Nordic Area" (Royal Gustavus Adolphus Academy, 2007). The party wasn't just about purity; women would stay up late feasting and drinking. In 1649, the town of Uppsala actually banned mökvällarr. Apparently, guests were having a hard time maintaining decorum at the wedding service the next day.

One of the earliest recognized pre-wedding customs practiced by men took place in ancient Sparta, where soldiers would toast one another on the eve of their friend's wedding, Brand wrote. But a key moment in the formation of modern bachelor-party traditions was the 19th-century Industrial Revolution. 

"You've got a lot of people moving away from the countryside and into the cities, and almost having to recreate rituals," Thurnell-Read said. Boys were going to work in workshops and factories from an early age — so that's where these rituals took place. 

At particular rites of passage, such as when a boy finished an apprenticeship, men treated one another to beers at a pub and played practical jokes on one another, hiding one anothers' boots and tools and filling their overcoats with tar and feathers. These traditions were precursors to the traditions we see today with bachelor parties, Thurnell-Read said. 

When women joined the workforce at the beginning of the 20th century, they adopted their own workplace traditions, which then morphed into pre-wedding celebrations. For example, co-workers would shower the bride with gifts she'd need as a wife, such as kitchen utensils — an early incarnation of the bridal shower, wrote Beth Montemurro, a distinguished professor of sociology at Penn State Abington, in "Something Old, Something Bold: Bridal Showers and Bachelorette Parties" (Rutgers University Press, 2006).

Still, debauchery wasn't an element of most festivities (with perhaps one notorious exception: the 1896 party of Herbert Barnum Seeley for his brother, which was shut down by police due to rumors that a belly dancer would perform nude). At least, not until the Sexual Revolution of the 1960s, Brand wrote. It became more common for men to celebrate bachelor parties as a last hurrah before marriage. And with the advent of a new wave of feminism that focused on equality, women began celebrating more like men, Montemurro wrote. 

Related: Why do people ghost?

Since then, bachelor and bachelorette parties have become increasingly elaborate affairs, Thurnell-Read said. Part of that has to do with what we see in the media: "The last few years, we've had a steady stream of cultural representations of the bachelor party," Thurnell-Read said. (Perhaps most notably "The Hangover" movie series, which sparked a bachelor party industry in Thailand, where the 2011 film "The Hangover Part II" was filmed.) These depictions put pressure on the best man or maid of honor to really deliver on the party planning, he added. 

But with changing notions of gender and sexuality, these parties are also changing, Thurnell-Read said. More and more, men and women celebrate together. And there's a movement away from heavy drinking. He sees more men opting to go mountain biking, for instance, rather than out to bars. And with increasing geographic mobility and people marrying later in life, the tradition is less about debauchery and more about gathering friends from multiple stages of life. 

"It's that bonding ritual that takes multiple smaller friendship groups and binds them together," Thurnell-Read said.

Originally published on Live Science. 

Science is supposed to be objective — right? By following a careful set of steps, it can tell us how the world works. But looking back on history, that's not at all true, experts say. In reality, science was used again and again to reaffirm whatever prejudices were in vogue at the time — including the idea that women are weaker, crazier, less smart and generally less capable than men. 

Here are seven hysterical ideas about women that were once scientific dogma.

Those pesky wombs cause all sorts of problems 

Feeling a little off? If you have a womb, you might want to make sure it hasn't wandered out of place, according to ancient Greek and Egyptian doctors. Hysteria, a condition described in the oldest medical document ever recovered, was attributed only to women. Its symptoms were mainly psychiatric and ranged from depression to a "sense of suffocation and imminent death," according to an article published in 2012 in the journal Clinical Practice and Epidemiology in Mental Health. 

Hysteria happened, scientists from the second century B.C. believed, when a womb just would not stay put. (The word "hysteria" even comes from the Greek word for womb, "hustera") Depending on whom you consulted, cures ranged from sexual abstinence to prescribed sex. Or perhaps, some argued, an herbal mixture would be sufficient to fix the problem.

By the 19th century, physicians no longer believed that the womb wandered. But many of the ideas underlying the concept of hysteria — for instance, that female reproductive organs could be blamed for psychiatric problems — stuck around. In fact, as late as 1900, many asylums still performed routine gynecological examinations on their patients , according to a 2006 article written by University of Manchester historian Julie-Marie Strange and published in the journal Women's History Review.

A vibrator could solve all our problems

By the early 20th century, when Sigmund Freud was revolutionizing the field of psychiatry, men and women both received treatment for hysteria. Even then, some doctors still attributed the condition to sexual or reproductive dysfunction in women. Some doctors would use streams of water to induce "hysterical paroxysm" (otherwise known as an orgasm) in women. In the 1880s, Dr. Joseph Mortimer Granville invented a medical tool especially for inducing these paroxysms and curing hysteria, Vogue reported. That tool eventually evolved into the vibrator.

Doctors should be careful not to excite women's passions "too much"

While some doctors prescribed sex to cure women of mental illness, other physicians worried that routine medical checkups might be a little too titillating. In an 1881 issue of the prestigious medical journal The Lancet, doctors said that gynecological exams could "ignite sexual passions in women" and encourage women to "satisfy their own lusts." One husband at the time even complained that the speculum had caused the downfall of his marriage, Strange wrote in Women’s History Review. 

Speaking of your womb, did you know it could fall out if you run too much?

In 1967, Kathrine Switzer became the first woman to officially sign up for the Boston Marathon — but race officials didn't know she was a woman. When she told her male training partners she was planning to run the race, they protested, Switzer wrote in her memoir. They thought it was too much for a fragile woman's body, fearing that her uterus might even fall out. 

This myth might come from a journal article published in 1898 in the German Journal of Physical Education, according to a 1990 study in the Journal of Sports History. In that 1898 study, a Berlin doctor wrote that exertion could cause the uterus to shift position in the body, resulting in sterility, "thus defeating a woman's true purpose in life." 

Today, with more women entering endurance sports, the idea that too much jiggling will cause your uterus to fall out has also fallen out of favor. But the notion still occasionally crops up. In 2005, Gian-Franco Kasper, the president of the International Ski Federation, said on NPR that ski jumping is "not appropriate for ladies from a medical point of view." In 2010, he elaborated on his point by arguing that a woman's uterus could burst when she landed, Outside magazine reported.

Women are basically small men

Until very recently, doctors and scientists considered women, medically speaking, basically the same as men. 

"For a very long time, researchers in many fields believed there was a single body and that it was not gendered at all," Naomi Rogers, a historian at Yale School of Medicine, told Live Science.

That is, men were considered the default setting and women were variations on that mold. In fact, it was only in 2000 that the medical community formally acknowledged that "women are not small men," Vera Regitz-Zagrosek wrote in the book "Sex and Gender Aspects in Clinical Medicine" (Springer 2012). This assumption has had profound implications for female patients.

For example, until 2000, women were not always included in clinical trials — meaning that many drugs had been tested only on men, with no sense of how the medications might interact with a woman's body.

But weirdly, our brains are totally different

One of science's more persistent ideas about women is that they're fundamentally different from men in behavior and intelligence due to differences in their brains. That idea began with the field of phrenology, the study of head size that reached peak popularity in the 19th century. For years, scientists argued that women's smaller heads were a sign of their inferior intelligence. 

Later, scientists realized that women actually had larger heads in proportion to their bodies. So, researchers proceeded to argue that because women's proportions are more similar to those of children (who also have proportionally larger heads), women must be intellectually similar to children, wrote Margaret Wertheim in the book "Pythagoras's Trousers: God, Physics and the Gender War" (W. W. Norton & Company, 1997). 

"You can see the incredible appeal of brain size” as a measure of intelligence, Rogers said. But, she added, phrenology has long been debunked as pseudoscience.

Unfortunately, the idea that differences in female and male brains account for fundamental differences in personality and behavior still arises, Susan Castagnetto, a philosopher at Scripps College in California, told Live Science. For example, differences in the proportion of gray matter and white matter have been used to argue that men are more "systematizing" and that women are more "empathizing." 

But, Castagnetto pointed out, there's one major problem with this field of research: We don’t know what this difference actually does. "How do you conclude anything about actual performance based on finding [anatomical] sex differences in the brain?" she said.

There may be differences between male and female brains, but we can't conclude what those differences mean, Castagnetto said.

Periods make women even less fit

Another age-old idea is that people who menstruate are less capable of performing tasks — like leading, attending school or even being good mothers. Beginning in the Victorian era, doctors referred to menstruation as an illness or a disability, Strange wrote. In an article titled "Sex in Education: or a fair chance for the girls," American Doctor Edward Clark wrote that because women menstruate, they have less blood overall compared to men, and therefore less energy. He extrapolated that because of their limited blood supply, school would downright dangerous for girls. After all, he argued, studying could divert a girl's limited blood supply away from vital organs (like her uterus and ovaries).

Though the idea of "limited blood supply" seems comical today, the notion that people who menstruate become indisposed once a month has stuck around. In 1975, Psychology Today ran an article titled "A person who menstruates is unfit to be a mother," Carol Tavris wrote in her book "The Mismeasure of Woman" (Touchstone, 1992). Today, a host of undesirable symptoms — from confusion to asthma to lowered school performance — are all chalked up to menstruation under the name premenstrual syndrome (PMS), Tavris wrote.

"Mercy!" she wrote. "With so many symptoms, accounting for most of the possible range of human experience, who wouldn't have PMS?"

Editor's Note: This story was updated to correct Susan Castagnetto's area of expertise. She is a philosopher, not an ethicist.

Women who trekked across Antarctica in the first-ever all-female expedition broke more than gender norms — they also busted the gender myth that, when it comes to extreme endurance exercise, women are weaker than men.

Sorry men, that's not the case.

"Our findings contain some potentially myth-busting data on the impact of extreme physical activity on women," lead study author Dr. Robert Gifford, of the University of Edinburgh's Centre for Cardiovascular Science, said in a statement. "We have shown that with appropriate training and preparation, many of the previously reported negative health effects [of extreme exercise on women] can be avoided."

The new findings — presented today (Nov. 19) at the Society for Endocrinology's annual meeting in Glasgow, Scotland — contradict some previous research that suggested women experienced more negative effects on their hormone and stress levels than men in response to extreme physical activity. [Men vs. Women: Our Key Physical Differences Explained]

For example, some studies have reported that extreme exertion can suppress female reproductive hormones, impair bone strength and increase levels of stress hormones to a greater degree than in men. But the reasons for these reported differences were unclear.

Into the ice

To better understand the effects of extreme endurance on women, researchers in the new study examined members of the Ice Maiden team, a group of six women from the British army who became the first all-female team to ski across Antarctica. During the two-month journey (from November 2017 to January 2018), the women covered more than 1,000 miles (1,700 kilometers) while pulling 170-pound (80 kilograms) sledges behind them, according to the BBC. The women faced treacherous conditions, including 60-mph winds and temperatures as low as minus 40 degrees Fahrenheit (minus 40 degrees Celsius).

Before, during and after the expedition, the researchers monitored several markers of health, including indicators of stress, hormone levels, body weight and bone strength.

During the expedition, the women lost about 20 pounds (9 kg) of fat mass each, but they did not lose any lean mass, the study found.

In addition, markers of metabolic, hormonal and bone health were largely unaffected by the trip, and those that did change went back to normal shortly afterward.

The findings demonstrate "marked resilience" in hormonal function, stress response and bone strength in women in response to extreme endurance exercise, the researchers wrote in their study abstract.

The researchers note that the women underwent rigorous training before the expedition, which may have helped mitigate any negative health effects.

The researchers plan to further investigate the types of activities and circumstances that contribute to negative health effects caused by physical exertion, and how the effects can be prevented.

"These findings could have important relevance for men and women in arduous or stressful employment, where there is concern that they are damaging their health," Gifford said. "If an appropriate training and nutritional regime is followed, their health may be protected."

• 5 Myths About Women's Bodies
• Female Firsts: 7 Women Who Broke Barriers in Science and Tech
• 10 Amazing Women Who Turned the Tide of History

Originally published on Live Science.

Women who have gone on a diet alongside men may have noticed a frustrating outcome: The pounds seem to fall off the men, while stubbornly sticking to women. Now, a new study delves into differences that take place when men and women diet — and confirms that, yes, men do lose weight faster.

In the study, published online Aug. 7 in the journal Diabetes, Obesity and Metabolism, the researchers tracked more than 2,000 overweight adults with prediabetes from Europe, Australia and New Zealand. For eightweeks, the participants followed an 800-calorie, mostly liquid diet that consisted of soups, shakes and hot cereals, plus a daily intake of 1.5 cups (375 grams) of low-calorie vegetables, such as tomatoes, cucumbers and lettuce.

At the end of the eight weeks, 35 percent of the men and women had normal blood-glucose levels and no longer had prediabetes, according to the findings. (Prediabetes means that a person has slightly elevated blood-sugar levels— a change that raises his or her risk of developing type 2 diabetes.) In addition, the researchers found that the men lost about 26 lbs.(11.8 kilograms), on average, over eightweeks, compared with about 22 lbs.(10.2 kg), on average, in women. [The Science of Weight Loss]

But it wasn't just that men dropped more total pounds than women — the researchers also found that men had larger reductions than women on other measures linked with better health, such as a lower heart rate and less body fat as well as a decreased risk of diabetes and metabolic syndrome. The latter refers to a collection ofsymptoms, such as high blood pressure and body mass index (BMI), that can raise risk for diabetes and heart disease.

The low-calorie diet affected womendifferently in other ways, the researchers found — and not all of the differences were positive. For example, compared with men, women experienced larger reductions in HDL cholesterol, the so-called good cholesterol—a change that could be bad for heart health. What's more, women in the study saw larger reductions in both bone mineral density, which may indicate weaker bones, and lean body mass, meaning less muscle. However, women did lose more inches in their hips than men. 

Gender-specific differences

The study confirms what any woman who has gone on a diet at the same time as her husband has already observed — men typically lose weight faster than women, said Dr. Elizabeth Lowden, a bariatric endocrinologist at Northwestern Medicine's Metabolic Health and Surgical Weight Loss Center at Delnor Hospital in Geneva, Illinois, who was not involved in the new study.

What's more, the gender differences in weight loss and improved health outcomes observed in this study physiologically make sense, Lowden told Live Science.

Men, thanks to their body composition, have more muscle and a higher metabolic rate than women, Lowden said. Since all of the participants were following a roughly 800-calorie-a-day diet, and men typically consume more daily calories than women when following their usual diets, they would have experienced a larger caloric deficit on the study diet and thus would be expected to lose weight faster than women, she said.

But the study went one step further to show different metabolic effects of the diet in men when compared towomen. Men typically have more weight in their midsection, known as visceral fat, which surrounds the internal organs, Lowden said. When peoplelose visceral fat, it improves their metabolic rate, helping them to burn more calories, she explained.

Women, on the other hand, typically have more subcutaneous fat, which is fat around their thighs, rear and hips that is important for childbearing, Lowden said. When people lose subcutaneous fat, this does not improve their metabolic risk factors, because this type of fat is not metabolically active, she explained.

Indeed, in the study, the researchers pointed to previous research that has suggested that the differences in metabolic outcomes observed in men and women who follow the same diet could be because men may mobilize more fat from their abdomens during weight loss, while women may lose more subcutaneous fat.

Still, though overweight men and women may experience some different health effects during a low-calorie diet, weight loss is always beneficial, Lowden said.

One of the limitations of the study is that it did not indicate whether some of the women participants had gone through menopause, Lowden said. After menopause, women tend to hold onto fat around their midsection like men do, and have more metabolically active fat, which could influence the results, she said.

Another limitation of the study is that the findings only focused on short-term changes and not on whether the weight lost by the participants and the health benefits achieved could be maintained over a longer period of time, the researchers wrote.

Originally published on Live Science.

Every kid is different and thus has different needs. Some kids want to run around outside all day; others want to sit indoors with a book. Some have an easy time making lots of friends; others struggle. Some kids are entirely comfortable with the gender they were assigned at birth, and others don't conform quite so neatly to expectations.

Parenting any kid is a challenge. But one challenge parents of gender-non-conforming kids — that is, those whose gender expression is different from conventional expectations of masculinity and femininity — face is that it can be hard to get good information about the sort of support their kids need. (Not all gender-non-conforming people identify as transgender — a term that describes people whose gender identity or gender expression differs from what's typically associated with the gender they were assigned at birth — and vice versa, according to GLAAD.) A Google search on care for gender-non-conforming or transgender kids turns up a lot of misinformation, including about what good support for trans kids really looks like.

Live Science spoke with pediatricians who responsibly affirm and support gender-non-conforming and trans kids about the facts and myths of medical care for these young individuals. They answered questions about what parents can do to support their gender-non-conforming children and how they can ensure their children receive the best possible care. [25 Scientific Tips for Raising Happy (& Healthy) Kids]

The first step is always a conversation, led by the patient.

Dr. Daniel Summers, a Boston-area general-practice pediatrician, said he makes an effort to understand his young patients' gender expression on their terms — particularly when they tell him that they're not comfortable with the gender they were assigned at birth or that they belong to a different gender.

"I find out: 'Well, what does that mean to you?'" he said. "'Does that mean that this is how you've been able to live? Is this how you're wanting to live? Is this something you've been able to tell other people about?'"

Summers and two other pediatricians told Live Science that their goal is never to encourage patients to express a particular identity. Rather, he tries to create a space where they're comfortable frankly discussing their own feelings on the matter.

Dr. Andrew Cronyn, a pediatrician in Tucson, Arizona, who has seen more than 70 gender-non-conforming patients as a routine part of his general practice, said some kids state a clear gender preference from a very young age.

"For some of these kids," he said, "it means that when they were 3 years old, they started asking their parents questions like, 'When am I going to grow a penis? Why do I have to wear these boy clothes all the time? Why can't I wear a dress? I'm not a boy. I'm a girl.'"

Other kids' gender expressions are more ambiguous, he said.

Dr. Olivia Danforth — who sees young patients in Corvallis, Oregon, and helps run a clinic for trans adults — said that, in those cases, her role is to provide parents and kids with information, reassure them that their situation is normal and let them know about resources they can access if the kids' gender identities become a source of distress.

Cronyn said he often connects parents with local support groups and summer camps for families with gender-non-conforming kids.

The goal there, he said, is "giving people a chance to meet these other families. And sometimes, they will go … then talk to their kid, and they'll realize that this isn't really the route they're on — it's a little boy who wants to wear nail polish, but he's not transgender," Cronyn said. "And he's perfectly happy with his body and his gender right now."

But sometimes, he said, a child will express that they do want to transition — meaning to affirm publicly the gender they know themselves to belong to. The best thing parents and healthcare providers can do for those kids, he said, is to follow their lead.

Kids, not doctors, lead the way when they transition.

The first step in transitioning, Cronyn said, isn't medical. It's social.

That's especially true in kids who haven't yet entered puberty and whose bodies don't yet bear many obvious markers of sex, he said. Kids will let their friends at school, teachers and wider families know about their genders. That can often involve taking a new name, and it almost always involves letting people know the correct pronouns to use with them.

Often, kids who transition will also make changes to the way they dress to clearly mark their genders — though Danforth said it's important to understand that (just like their cisgender, or non-transgender, peers) not all trans kids will want to dress in ways stereotypical of their genders. [Why Is Pink Associated with Girls and Blue with Boys?]

Cronyn said he often sees a difference between how trans boys and trans girls handle transitions.

"Some of the boys will immediately socially transition," he said. "They will cut their hair short, wear boy clothes. They might wear binders; they might wear a packer."

Girls can be a little more cautious, he said. "A lot of times, they realize the safety issues related to someone seen as masculine presenting as a woman," Cronyn said.

Trans girls in his practice often take the process of coming out more slowly, he said, but they tend to be just as consistent in their intent to transition as trans boys are. The most important thing parents, family and friends can do when a child socially transitions, Danforth said, is to respect and affirm the gender that the child expresses.

Prepubescent kids don't take hormones, and minors never get genital surgery.

A lot of scaremongering about health care for trans kids falsely suggests that doctors push kids into making permanent changes to their bodies. Every pediatrician who spoke with Live Science for this story emphasized that this isn't true and that they don't know of any doctors who would do that.

Kids who haven't yet reached the stage of puberty in which physical changes begin don't receive medication of any kind, Cronyn said. For kids who want them, those treatments don't begin until puberty begins in earnest. And the first stage of treatment isn't hormones. Instead, doctors prescribe kids puberty blockers, which can safely put those changes on "pause." That's the standard of care endorsed by both the Pediatric Endocrine Society (PES) and the World Professional Association for Transgender Health (WPATH). (A representative for the American Academy of Pediatrics told Live Science that it has an official policy statement on the subject in the works, which it will publish later this year.)

There is some limited evidence that puberty blockers can impact height and bone density, but Cronyn said those risks are low enough that he's never encountered issues in his practice. More recent research has cast doubt on the idea of bone density issues.

In his clinic, Cronyn said, no child ever receives any medication related to transitioning unless they've been demonstrably "insistent, consistent and persistent" about their gender for at least six months. (Again, this in keeping with PES and WPATH guidelines.)

At the same time, Danforth said, parents should be aware that there are some doctors who take that idea too far.

"The big caution I think — that may be hard for parents who are nervous to resist — is to pay attention to what kind of terms and conditions a provider wants to attach to care," she said. "There has been a historical tradition of making patients jump through hoops and sort of perform in these arbitrary ways."

For example, she said, trans girls might be expected to always wear a dress and paint their fingernails to "prove" their genders, even though there are plenty of cisgender girls who don't do either of those things. Acting overtly, stereotypically masculine or feminine, she said, isn't a condition a responsible doctor sets before pausing puberty.

Why pause puberty? There's a real risk, Danforth said, that kids might hurt themselves or even attempt suicide if their bodies start to develop in ways that trigger debilitating dysphoria (a sense of conflict between one's gender identity and physical or social presentation).

There's evidence for the idea that supporting trans kids in their transitions can protect their mental health. A 2015 study published in The Journal of Adolescent Health showed that trans kids in general are at much higher risk of suicide, but a 2016 study in the journal Pediatrics showed that teenagers who are supported in their transition seem to be no more depressed and only slightly more anxious than their cisgender peers.

Adolescent mental health isn't the only reason for puberty blockers though, Cronyn said. Even trans kids who don't go through self-harm during unchecked puberty are at risk of developing unwanted physical traits that are difficult or impossible to reverse. Puberty blockers, he said, are a safe and effective way to ward off life-altering physical problems without starting kids on hormones before they're ready — or before most doctors are comfortable prescribing them. The point, Danforth said, is to protect kids from having to go through a puberty that isn't right for them.

"If you never fully develop breasts, you're never going to have to have chest reconstruction," Cronyn said. "If you never develop an Adam's apple, you're never going to have to have your Adam's apple shaved."

In addition, kids, with medical guidance, can decide to stop taking these puberty blockers so that puberty will begin on its own.

A lot of discussion of transitioning focuses not on puberty blockers or hormones, but on the idea of surgery. However, Cronyn, Danforth and Summers said, the notion of trans kids getting surgery is largely a myth.

Clinics simply don't offer "bottom" surgery of any kind — meaning surgery to change a person's genitals — to children under the age of 18. And while the World Professional Association for Transgender Health (WPATH) guidelines do allow "top" surgery — surgery to remove breasts and reconstruct the chest — for certain adolescent boys "after ample time of living in the desired gender role and after one year of testosterone treatment," that course of treatment isn't common.

Hormones don't start until much later in the transition process.

The point of trans kids receiving hormones is to enable their bodies to develop in line with their genders, Cronyn said. And kids never receive them unless they've reached puberty and have expressed consistently and persistently that they want to receive them.

Once kids do begin to take hormones, Cronyn said, they'll go through puberties that are, in most respects, indistinguishable from those of their cisgender peers. Boys' voices deepen more than girls'; they develop Adam's apples and facial hair; and they develop testosterone-driven facial structures. Girls develop breasts; their voices don't deepen as much as boys'; and they develop estrogen-driven facial structures.

Typically, Cronyn said, trans girls remain on puberty blockers for as long as their bodies still produce high levels of testosterone, while trans boys can stop taking them as soon as they begin taking hormones, because "testosterone is a bulldozer."

Hormones do change the kinds of medical risks these kids face, he said — trans boys on hormones are at increased risk of baldness, for example, and trans girls on hormones are at increased risk of blood clots — but those risks aren't that different from their cisgender peers'.

The most significant difference between puberty on hormones and most non-drug-induced puberties, Cronyn said, is fertility. Hormones can make it difficult for trans people to have biological children. Some patients and their families elect to store eggs and sperm before hormones begin, he said, though that can be an expensive and sometimes difficult process.

"The thing that we also have to look at, though, is the risk of not treating [gender-non-conforming kids]," he said.

Kids who have treatment withheld, or who are pushed to suppress their genders, are at significant risk of self-harm and other mental-health issues.

"Doing nothing is not a benign action," Danforth said. "It's not neutral, because [the kids] aren't getting a choice in what's happening to their bodies."

Forcing a trans kid to go through puberty without blockers or hormones, perhaps with the idea that they can transition as adults, does a lot of harm and no good, she said.

"We know for a fact that whether these kids are accepted or rejected, it's never going to affect whether they are trans or not, or whether they are the gender that they are or not," Danforth said. "But it is a life-or-death thing. There are potentially lives being lost in failing to be supportive and compassionate about this stuff."

The most significant debate among responsible doctors, Danforth and Cronyn said, isn't about providing hormones to kids but about when to start. Current standards, based on the age of consent in the Netherlands, instruct doctors to wait until a kid turns 16 to start them on hormones.

Cronyn and Danforth argued that, in some cases, the long wait can be irresponsible, putting the child in the position of remaining prepubescent until their sophomore year of high school. Some doctors, they said, are starting to seriously consider offering hormones earlier to kids who want them.

Originally published on Live Science.

A transgender woman was able to produce enough milk to breast-feed her partner's newborn baby for six weeks, according to a new report of the case.

The report is the first in the medical literature to formally document lactation in a transgender woman, the researchers said.

The transgender woman was able to breast-feed after undergoing a regimen of hormonal therapy along with the use of a breast pump, in a process similar to what's done for women who cannot produce breast milk on their own (including women who want to breast-feed after adoption). [Men vs. Women: Our Key Physical Differences Explained]

"We want to present our patients with the full range of reproductive choices, and this is one step closer to that," Dr. Tamar Reisman, an endocrinologist at Mount Sinai hospital's Center for Transgender Medicine and Surgery in New York, told the Washington Post.

The report was published in the January issue of the journal Transgender Health.

It's known that people who are born male can produce milk — for example, men who undergo hormonal treatment for prostate cancer can, in some cases, develop breast fullness and lactate, said Dr. Maurice Garcia, the director of the Transgender Surgery and Health Program at Cedars-Sinai Medical Center in Los Angeles, who was not involved with the case. However, men don't usually lactate much because of the differences in hormone levels between men and women. But the new case shows that this transgender woman produced enough milk to sustain a baby for six weeks, which is "terrific," Garcia said.

The report underscores the anatomic similarity between the sexes, which is greater than many people appreciate, Garcia told Live Science. It's "encouraging that we can build on this anatomic homology between the genetic sexes … to help [transgender people] bring their bodies more in line with their gender."

In the new case, the patient first began taking feminizing hormones in 2011 as part of her gender transition. Then, in 2017, she asked her doctor about the possibility of breast-feeding her partner's baby. Her partner was pregnant at the time, but did not plan on breast-feeding. The transgender woman hoped to be the primary food source for the child, whom she would also adopt, the report said.

The patient underwent a three-month course of treatment, which included the drugs domperidone and the hormones estradiol and progesterone. (Domperidone is a drug that increases levels of prolactin, which aids in lactation. The drug is not approved for use in the United States, and the patient in this case obtained it from Canada.) She also took spironolactone, which blocks testosterone.

The woman breast-fed the baby for six weeks and then began supplementing the breast milk with formula because she was concerned that her milk supply had become insufficient for the child. The baby is currently 6 months old, and is growing and feeding normally, the report said.

More research is needed to optimize treatments for transgender women who want to breast-feed, the report said. For instance, it's not known whether all of the hormones and drugs used in this case were needed to achieve lactation, or whether adjusting the doses could lead to even greater milk production.

Original article on Live Science.

This article was originally published at The Conversation. The publication contributed the article to Live Science's Expert Voices: Op-Ed & Insights.

Gender is generally thought of as a stable trait: we are born male or female and we stay that way as we grow from small children to adults.

It turns out that for young children, initial concepts about gender are quite flexible. In my own research, I've found that children don't begin to notice and adopt gender-stereotyped behaviors (e.g., preferring colors like pink or blue) until the age of two or three. A few years later, their concept of gender becomes quite rigid, and although it becomes more relaxed by middle childhood, even adults have trouble going back to thinking about gender as something that's flexible.

So, how do children come to understand gender? When do they begin to think about gender as a stable trait?

What is gender?

We often tend to think about gender as the biological differences between men and women.

It is true that the path to gender development begins at conception. Each cell in our body has 46 chromosomes. A father's sperm and a mother's egg each has only half – 23 each. At conception, the chromosomes of the sperm and the egg match up into 22 identical pairs, with the 23rd pair being the sex chromosome. In most cases, XX chromosomes will become female and XY chromosomes will become male.

But this isn't always the case. Gender is what actually gets expressed – how we look, how we act and how we feel. While sex is determined by what is written into the chromosomes or what is dictated by our biology, known as genotype, it is the interaction between the genes (genotype) and the environment that determines gender.

Sex doesn't necessarily map to gender perfectly, and the environment plays a role in determining the gender of each person.

Perhaps this shouldn't be that surprising, given that the sex of many species of animals is determined entirely by environmental circumstances and not by their biology. For example, there are animals that don't have sex chromosomes at all, and some species of coral reef fish can actually switch genders if their schools require it. Alligators, crocodiles, turtles and some lizards don't have sex chromosomes either: their sex is simply determined by the temperature of their nest during incubation.

It's true that most of the time, a person's sex and gender are quite similar, but this doesn't necessarily have to be the case. And of late, the lines between sex and gender are becoming more blurred as people are becoming more comfortable identifying as transgender – or with a gender that is not consistent with their sex. In fact, for some people, gender is nonbinary, and exists on a spectrum of masculinity and femininity.

Children's early gender concepts

So it turns out that gender is more of a flexible state than most people think. And surprisingly, as children, we start out thinking more flexibly about gender than we end up.

Before the age of five, children don't seem to think that gender has any permanence at all. A preschooler might ask his female teacher whether she was a boy or girl when she was little, or a little boy might say that he wants to grow up to be a mommy.

Research supports this early flexibility in children's gender concepts. For example, in a well-known study, psychologist Sandra Bem showed preschool-aged children three photographs of a male and female toddler.

In the first photo, the toddler was naked; in the second the toddler was dressed in gender-typical clothing (e.g., a dress and pigtails for the girl, a collared shirt and holding a football for the boy); in the third photo, the toddler was dressed in stereotypical clothing of the opposite gender.

Bem then asked the children a variety of questions. First she asked them about the photo of the naked toddler and the photo of the toddler dressed in gender-typical clothing, asking children whether the toddler was a boy or a girl.

She then presented the children with the same toddler dressed in opposite-gendered clothing. She told them that the toddler was playing a silly dress-up game, and made sure that the first nude photo of the toddler was still visible for reference. She then asked the children whether the toddler in the third photograph was still a boy or a girl.

Most three- to five-year-olds thought that a boy who decided to dress up like a girl was now indeed a girl. It wasn't until children understood that boys have penises and girls have vaginas that they also knew that changing your clothes doesn't change your gender.

Developing gender identity

Further research suggests that children's concept of gender develops gradually between the ages of three and five. After the age of five, most children believe that outward changes in clothing or hairstyle don't constitute a change in gender.

Once children begin to think about gender as a stable trait, they also start to incorporate gender into their own identity.

Around that time, they become motivated to relate to other members of their group and seek out gender-related information, often becoming very strict about adhering to gender stereotypes. For example, children between the ages of three and five prefer to play with members of their own gender. And they also prefer to engage with gender-stereotyped toys and activities.

It isn't until a few years later – when they are between seven and 10 years of age – that children become more relaxed about maintaining behaviors that are strictly male or female. It is around that age, for example, when both boys and girls might admit that they "like to play with trucks" or "like to play with dolls."

Ahead of their time?

Recent media attention on transgender people has once again drawn our attention back to the fact that while our chromosomes determine our sex, they are not the only factors that affect our gender identity.

This is something that children seem to know early on, but that most discard as they begin to learn about basic anatomy and incorporate that information into their own gender identities.

We often think of children's thinking as immature, but it may be that preschoolers are actually way ahead of their time.

Vanessa LoBue, Assistant Professor of Psychology, Rutgers University Newark

This article was originally published on The Conversation. Read the original article.

After three years of improvement, the well-being of Americans ticked downward in 2017, according to a new poll, though some demographics were spared.

The overall well-being of U.S. adults dropped to a score of 61.5 on a scale of 100, down 0.6 points from 62.1 in 2016, according to the latest Gallup-Sharecare survey, which was published yesterday (Nov. 8).

The score, called the Gallup-Sharecare Well-Being Index, ranges from zero to 100, with zero representing the lowest possible well-being and 100 representing the highest.

To calculate the Well-Being Index, the researchers looked at five metrics: whether a person felt a sense of purpose in daily life, whether they enjoyed supportive relationships, their level of financial security, whether they felt safe and happy in their community and whether they were in good physical health, according to Gallup. [Find Out Where Your Country Ranks on the Happiness Index (Infographic)]

Though the overall findings show a decrease in well-being, the effects weren't felt across all demographics. For example, the survey found that both men and Republicans fared just as well in 2017 as they did in 2016. But women's well-being dropped by 1.1 points from 2016 to 2017, and Democrats' well-being decreased by 0.9 points in the same time period. Black and Hispanic people had larger declines in well-being than other groups, at 1.3 and 1.0 points, respectively.

Only one group surveyed reported having a better Well-Being Index score in 2017, the researchers found: people making over $120,000 per year. For individuals in this group, the score increased by 0.3, but the researchers noted that the increase may fall within the margin of error for the survey, meaning the difference between 2016 and 2017 was too small to definitively say that there was a real change. Similarly, the very small drop in well-being for white people in the United States also may have fallen within the margin of error.

Compared with 2016, Americans said they worry more on a daily basis, according to the results. Of all the people who responded, the number of people who said that, at least some days each week, they have little interest or pleasure in doing things went up by 7.4 percentage points, from 33.7 percent in 2016 to 41.1 percent in 2017. Overall, the survey revealed that a smaller percentage of people felt that their community leaders fostered a feeling of enthusiasm about the future, and a smaller percentage of people in 2017 said they enjoyed their daily lives, compared with the percentage in 2016.

The survey results are based on telephone interviews with more than 135,000 U.S. adults from all 50 states and Washington, D.C., conducted from Jan. 2 to Sept. 30 of this year.  

Originally published on Live Science.

A fertility doctor says that in theory, men could attempt to get pregnant as soon as "tomorrow" thanks to advances in uterus transplant surgeries. But other experts say that such a procedure won't happen anytime soon because many more studies are needed to know whether it could be done safely.

Dr. Richard Paulson, the outgoing president of the American Society for Reproductive Medicine (ASRM), said he thinks it would be possible to perform uterus transplants on transgender women, who are born male and transition to female, according to The Telegraph. Speaking at ASRM's annual meeting, he said he sees no biological reason why the procedure wouldn't work in the male body.

"You could do it tomorrow," Paulson was quoted as saying. "There would be additional challenges, but I don't see any obvious problem that would preclude it. I personally suspect there are going to be trans women who are going to want to have a uterus and will likely get the transplant." [The 9 Most Interesting Transplants]

But other experts point out that the procedure isn't even mainstream for women, let alone men.

Uterus transplants are "still highly experimental," said Arthur Caplan, a professor of bioethics and head of the Division of Medical Ethics at New York University's School of Medicine. This means that the procedure is still being studied for its safety and effectiveness in women, and it is performed only as part of experimental trials.

Because of the additional research needed to understand the risks of the procedure and its effect on the fetus, performing a uterus transplant on a man right now would not be responsible, he said. "Surgically, could you put [a uterus] in a man tomorrow? Yeah, but it would be completely irresponsible," Caplan told Live Science.

Dr. Saima Aftab, medical director of the Fetal Care Center at Nicklaus Children's Hospital, agreed that the fertility treatment field has not yet reached the point where this procedure could be done in men.

"Even for women, there's still a reason for caution" as researchers collect more information about the safety procedure, Aftab said. "[We're] still far away from understanding enough to be able to do this safely in men," she said.

Uterus transplants are a relatively new procedure, with only about a dozen transplants performed so far worldwide. In Sweden, doctors have performed nine uterus transplants, and five of these women went on to successfully get pregnant and have children. But a recent uterus transplant in the United States failed after the organ became infected and had to be removed.

There are a number of risks involved with uterus transplantation, Aftab said. The surgery itself is a complicated procedure that requires the organ to be properly connected to the body's veins and arteries so that it has an adequate blood supply. If there is a problem with the blood supply, the organ will start to die, she said. In addition, people who undergo any organ transplant need to take medications to suppress their immune system so that the body does not reject the organ. But these medications can also increase a person's risk of developing infections.

In men, there could be several added risks. The surgery would be more complicated because the "body's anatomy is not naturally designed for there to be space and blood supply for the womb," Aftab said.

In addition, men do not produce the hormones needed to support pregnancy, so they would need a lot of hormone therapy to allow pregnancy to happen, which could introduce additional risks.

Animal studies likely would be needed to examine the doses of hormones needed to support pregnancy in men and to see whether the blood flow to the uterus is adequate after transplantation, Caplan said.

Finally, if a uterus transplant were to be performed on a person with male anatomy, that person would have to give birth via cesarean section because the male pelvis is too narrow for a baby to pass through, Aftab said. A C-section is also a major surgery that comes with risks. (Women who receive a uterus transplant also have to give birth via C-section because labor may be too stressful for the transplanted organ and because recipients do not feel contractions in the same way women who have traditional pregnancies do, according to Scientific American.)

Right now, the risks of the procedure for someone with male anatomy are so great, "it would be very difficult to think it's something that would be feasible in the short-term future," Aftab said. But it's conceivable that with additional research, doctors would get to a point where the risks are much lower, she said.

Original article on Live Science.

Five years ago, Silicon Valley was rocked by a wave of "brogrammer" bad behavior, when overfunded, highly entitled, mostly white and male startup founders did things that were juvenile, out of line and just plain stupid. Most of these activities – such as putting pornography into PowerPoint slides – revolved around the explicit or implied devaluation and harassment of women and the assumption that heterosexual men's privilege could or should define the workplace. The recent "memo" scandal out of Google shows how far we have yet to go.

It may be that more established and successful companies don't make job applicants deal with "bikini shots" and "gangbang interviews." But even the tech giants foster an environment where heteronormativity and male privilege is so rampant that an engineer could feel comfortable writing and distributing a screed that effectively harassed all of his women co-workers en masse.

This is a pity, because tech companies say they want to change this culture. This summer, I gave a talk at Google UK about my work as a historian of technology and gender. I thought my talk might help change people's minds about women in computing, and might even help women and nonbinary folks working at Google now. Still, the irony was strong: I was visiting a multibillion-dollar tech company to talk about how women are undervalued in tech, for free.

Facing common fears

I went to Google UK with significant trepidation. I was going to talk about the subject of my upcoming book, "Programmed Inequality," about how women got pushed out of computing in the U.K. In the 1940s through the early 1960s, most British computer workers were women, but over the course of the '60s and '70s their numbers dropped as women were subjected to intentional structural discrimination designed to push them out of the field. That didn't just hurt the women, either – it torpedoed the once-promising British computing industry.

In the worst-case scenario, I imagined my talk would end with a question-and-answer period in which I would be asked to face exactly the points the Google manifesto made. It's happened before – and not just to me – so I have years of practice dealing with harsh critics and tough audiences, both in the classroom and outside of it.

As a result of that experience, I know how to handle situations like that. But it's more than just disheartening to have my work misunderstood. I have felt firsthand the damage the phenomenon called "stereotype threat" can wreak on women: Being assumed to be inferior can make a person not only feel inferior, but actually subconsciously do things that confirm their own supposed lesser worth. For instance, women students do measurably worse on math exams after reading articles that suggest women are ill-suited to study math. (A related phenomenon, impostor syndrome, runs rampant through academia.)

A surprising reaction

As it happened, the audience was familiar with, and interested in, my work. I was impressed and delighted with the caliber and thoughtfulness of the questions I got. But one question stood out. It seemed like the perfect example of how the culture of the tech industry is so badly broken today that it destroys or significantly hinders much of its talent pool, inflicting stereotype threat on them in large numbers.

A Google engineer asked if I thought that women's biological differences made them innately less likely to be good engineers. I replied in the negative, firmly stating that this kind of pseudoscientific evolutional psychology has been proven incorrect at every turn by history, and that biological determinism was a dangerous cudgel that had been used to deprive black people, women and many others of their civil rights – and even their lives – for centuries.

The engineer posing this question was a woman. She said she felt she was unusual because she thought she had less emotional intelligence and more intellectual intelligence than most other women, and those abilities let her do her job better. She wondered if most women were doomed to fail. She spoke with the uncertainty of someone who has been told repeatedly that "normal" women aren't supposed to do what she does, or be who she is.

I tried to empathize with her, and to make my answer firm but not dismissive. This is how structural discrimination works: It seeps into all of us, and we are barely conscious of it. If we do not constantly guard ourselves against its insidious effects – if we do not have the tools to do so, the courage to speak out, and the ability to understand when it is explained to us – it can turn us into ever worse versions of ourselves. We can become the versions that the negative stereotypes expect. But the bigger problem is that it doesn't end at the level of the individual.

A problem of structure

These misapprehensions bleed into every aspect of our institutions, which then in turn nurture and (often unwittingly) propagate them further. That was what happened when the Google manifesto emerged, and in the media frenzy that followed.

That the manifesto was taken as a potentially interesting or illustrative opinion says something not just about Silicon Valley, but about the political moment in which we find ourselves. The media is complicit too: Some media treated it as noteworthy only for its shock value. And others, rather than identifying the screed as an example of the writer's misogyny, lack of historical understanding, and indeed – as some computer professionals have pointed out – lack of understanding of the field of engineering, handled the document as a think piece deserving consideration and discussion.

The many people who said openly and loudly that it was nothing of the sort are to be commended. But the fact that they had to waste time even addressing it shows how much damage casual, unreflective sexism and misogyny do to every aspect of our society and our economy.

The corporate response

Google, for its part, has now fired the writer, an expected move after the bad publicity he has helped rain down on the company. But Google has also – and in the very same week that I gave my talk there – refused to comply with a U.S. Department of Justice order to provide statistics on how it paid its women workers in comparison to men. The company claims that it might cost an estimated US$100,000 to compile that data, and complains that it's too high a cost for their multibillion dollar corporation to bear.

The company will not expend a pittance – especially in relation to its earnings – to work to correct allegedly egregious gender-biased salary disparities. Is it any surprise that some of its employees – both men and women – view women's contributions, and their very identities, as being somehow less inherently valuable or well suited to tech? Or that many more silently believe it, almost in spite of themselves?

People take cues from our institutions. Our governments, corporations, universities and news media shape our understandings and expectations of ourselves in ways we can only partially understand without intense and sustained self-reflection. For the U.K. in the 20th century, that collective, institutional self-awareness came far too late to save its tech sector. Let's hope the U.S. in the 21st century learns something from that history. At a time when technology and governance are increasingly converging to define who we are as a nation, we are living through a perfect – if terrifying – teachable moment.

Marie Hicks, Assistant Professor of History, University of Wisconsin-Madison

This article was originally published on The Conversation. Read the original article.

A Google employee recently published an anti-diversity manifesto on an internal discussion board that has gone viral and stirred furious debate both inside and outside the company.

In the essay, James Damore claimed that differences in the number of women and men in tech companies such as Google can be largely explained by biological differences, rather than sexism. As a result, some diversity efforts aimed at increasing the representation of women and other minorities are discriminatory against men, he argued. (After the memo went public, Google fired Damore for perpetuating gender stereotypes, Reuters reported.)

But what does science have to say about the biological differences between men and women, and how do they affect the gender gap in tech?

"It would be foolish to say there are no biological differences between men and women," said Margaret McCarthy, a neuroscientist at the University of Maryland who studies gender differences in the brain. "Sex is the most potent of all biological variables." [Men vs. Women: Our Key Physical Differences Explained]

However, pinning the lack of women in tech to biological differences is on much shakier ground, when socialization or sexism are much likelier explanations, several experts told Live Science.

Anti-diversity manifesto

In Damore's manifesto, he claimed that, compared with men, women on average are more attracted to aesthetics than to ideas, more empathizing than systematic and more extroverted than introverted, but less assertive and less competitive. As a result, he said, women may have more difficulty negotiating higher salaries, speaking up or asking for raises.

He also claimed that women exhibited higher neuroticism, which is manifested in lower stress tolerance and higher anxiety, and that women are less willing to work the long hours necessary to achieve high-paying, high-status jobs. In another section of the manifesto, he said people on the ideological left deny biological differences when they are tied to IQ and sex differences.

Different brains

It turns out, there are extensive neuroanatomical differences between men's brains and women's brains on average, said Larry Cahill, a neurobiologist at the University of California, Irvine. This shouldn't be surprising; after all, humans are mammals, and mammals exhibit extensive sex-based differences in brain chemistry, anatomy, genetics and function, Cahill told Live Science. 

McCarthy agreed.

"We are biologically different," McCarthy told Live Science. "It would be crazy to say that difference in biology doesn't to some degree extend to our brains. To think that we have somehow escaped millions of years of evolution because we're modern humans, I think, is just folly."

For instance, women on average have more gray matter, the computational workhorse of the brain, while men have more white matter, which connects brain cells in different regions of the gray matter. Men and women also have different connective networks between brain cells, on average, according to a 2013 study in the journal Proceedings of the National Academy of Sciences. What's more, men's brains tend to be larger than women's. And sex hormones such as testosterone and estrogen, which vary dramatically between men and women, also bind differently to receptors in the brain. [10 Surprising Facts About a Man's Brain]

However, these average differences do not make it possible to type individual brains: A 2015 study in the same journal found it was impossible to categorize most brains as stereotypically male or female based on gray matter in several brain regions.

"Gender differences, small or large, do not 'add up' to create two types of people," said Daphna Joel, a neuroscientist at Tel Aviv University in Israel who was one of the authors of the 2015 study. "Rather, each person has a unique mosaic of feminine (that is, more common in women than in men) and masculine (that is, more common in men than in women) psychological characteristics."

Similar behavior

Once scientists make the leap from brain anatomy to function, the connection gets even shakier. For instance, bird brains are smaller than mammalian brains, and they're wired very differently. Yet many birds can tackle brainy feats that stymie the smartest nonhuman mammals. Clearly, brain anatomy does not reveal the whole story, McCarthy said. [Are Big Brains Smarter?]

What's more, many differences in the structure of men's brains versus women's brains may actually counteract gender differences in behavior, a 2004 study in the journal Endocrinology found. For instance, women inherit two X chromosomes, while men inherit an X and a Y. But in women's brains, one of the X chromosomes is almost completely silenced to keep them from getting a double dose of gene expression, meaning that men's and women's brains express roughly the same number of X chromosome genes — even though, genetically, they have this chromosome difference.

Still, there's no reason to discount the possibility that anatomical or biological differences translate to behavioral differences, Cahill told Live Science.

"Is it inherently plausible that biologically based sex-related influences affect all aspects of human behavior, including careers people choose?" Cahill asked. "The answer is yes."

Manifesto claims

Still, many of the average differences between men and women that were described in the manifesto are either small or near zero, according to a 2005 study in the journal American Psychologist. Some, if not all, of the average differences could be due to socialization rather than biology, several experts said.

For instance, across cultures, men tend to be better at rotating objects in their mind than women are. However, in India, tribal women in matrilineal societies who hold the purse strings perform better at this task than women in nearby, genetically similar tribes, which are patrilineal. Education also dramatically shrinks this gap in spatial abilities, the researchers found.

In the United States, men outperform women on the math SAT, while in Japan, men and women perform equally well on the math portion of this standardized test — and outperform both their male and female American counterparts, McCarthy said. Meanwhile, in some Nordic countries, women outperform men on the math portion of the SAT.

Similar disparities in science versus reading abilities exist across countries, said Bernd Frick, a professor of organizational economics at Paderborn University in Germany. [6 Myths About Girls and Science]

"Girls are told that reading abilities are important. Boys are told that sciences are important, and you see that reflected in standardized tests with young kids ages 8 to 9 or 10 to 12," Frick told Live Science.

However, more patriarchal societies show a much larger gap in these test scores, while egalitarian cultures show only a tiny gap, he added. That suggests that culture, rather than brain differences, explains most of the gap, he added.

As for women's versus men's average intelligence (IQ), there is no average difference.

"That has been shown over and over and over with millions and millions of data points," McCarthy said.

Women do tend to exhibit higher rates of diagnosis with certain types of neuropsychiatric diseases, such as major depressive disorder, anxiety and obsessive compulsive disorder, McCarthy said. However, the difference in the gender ratio for anxiety is quite small compared with differences for other diseases such as anorexia nervosa or autism. Men are also less likely to seek out diagnoses and more likely to self-medicate with alcohol and drugs, meaning at least some of the gender difference in the rates of depression or anxiety could be due to underdiagnosis in men, not a differential response to stress, she added. [7 Ways Depression Differs in Men and Women]

"Is the gender difference in the level of stress you're manifesting, or is it that you're willing to admit you're feeling that stress and anxiety?" McCarthy asked. "These are very complex questions [that] we don't know the answer for."

Also, gender differences may wax or wane through the life span, making it difficult to tease out the effects of socialization versus biology. For instance, young girls tend to start out being much more aggressive and assertive but become less so by the adolescent years.

"Is it because they are punished for getting out of their 'gender lane,' or is it because they go through puberty?" McCarthy said. Right now, there's no way to know, she said.

Other work has shown that women are less competitive than men on average. However, a 2011 study of ultramarathoners, published in the Journal of Sports Economics, showed that as societies become more egalitarian and the prize money women compete for approaches the pots for men, the competitiveness gap disappears.

"So it's a matter of culture," Frick said.

Other explanations for the tech gap

The manifesto goes way out on a limb, however, when it aims to explain the gender gap in tech to biology when other factors such as sexism or outmoded family structures clearly play a role, McCarthy said.

For instance, several studies have shown that a powerful way to attract more women to leadership positions is to have more women in leadership roles, McCarthy said. So the dearth of senior women in tech could lead to a vicious cycle of under-representation, she added.

What's more, women do not inherently want to work fewer hours. Rather, many are expected to shoulder a second shift of childcare and chores when they get home, McCarthy said.

"They have two jobs," McCarthy said.

And sexism in the tech world isn't benign either, Cahill said.

"I always hear about a bro cultulre [in tech]," Cahill said. "It's probably the case that the average woman will chafe more at the average bro culture than the average man."

What's more, no studies have shown that the skills and personality traits needed for tech jobs are uniquely male. For instance, no studies suggest that being agreeable, empathetic or extroverted (the traits Damore ascribed to women) are liabilities for those in the tech field, McCarthy said.

"If Google needed only people with only extremely masculine characteristics, then there would be more suitable male candidates than female candidates," Joel said. "But even in the relatively narrow field of tech, there are many different combinations of characteristics (some more common in women and some more common in men) that fit, so sex differences in the prevalence of these mosaics is unlikely to explain the gender gap in tech."

Originally published on Live Science.

Work-life balance is often addressed as a women's issue. Facebook executive Sheryl Sandberg's book "Lean In" was directed at women, Anne-Marie Slaughter's essay in The Atlantic was about "Why Women Still Can't Have It All" and Ivanka Trump's recent book "Women Who Work" dismissed the very concept of women seamlessly blending paid work and family.

But an expansive new study of work-life conflict reveals that "having it all" isn't just a female problem. In fact, men report practically equivalent levels of struggle to balance work and everything else as women do. 

"It's just a huge disconnect, because the media almost always frames it as a women's issue," said study leader Kristen Shockley, a psychologist at the University of Georgia. In fact, Shockley told Live Science, studies on work-life balance and gender are "all over the place." Some find more struggles for women, and others for men; some find no difference at all. [Top 12 Warrior Moms in History]

Work and life

To make sense of all this conflicting research, Shockley and her colleagues conducted a meta-analysis, in which they pooled the data from multiple studies on the same topic. More data makes for firmer statistics and a clearer view of the big picture.

Pulling from 352 separate studies, Shockley and her team analyzed survey data from more than 250,000 individuals who had answered questions about how much their work and family life were in conflict. In some cases, those questions addressed how much family life interfered with work responsibilities. In other cases, the questions covered how much work intruded on family.

Overall, the researchers found, there was almost no correlation between gender and the experience of work-family conflict.

Women technically experienced more conflict, Shockley said, but the correlation between gender and conflict was a mere 0.017. A correlation of 1 would mean that work-life balance depended entirely on gender; a correlation of zero would mean there was no gender difference.

A correlation of 0.017, "practically speaking, is zero," Shockley told Live Science.

Digging deeper, the team tried to figure out if particular life circumstances, such as being a parent or working in a particular occupation, would make a difference in how the genders experienced work-life conflict. Again, they came up with very little. Mothers reported slightly more intrusion of family into work than fathers did, and women in dual-income couples reported slightly more intrusion of family into work than men in those couples did, but the differences were still very small, Shockley said.

"Compared to the way it's talked about, where you think women are experiencing so much more, it's pretty negligible," she said. "Men and women tend to experience similar levels of these conflicts."

Analyzing the emotions

"I'm not surprised by it at all," said Tammy Allen, a psychologist at the University of South Florida who was not involved in the research. One previous smaller meta-analysis had returned similar results, she said, and it was clear the research on the subject showed a less-clean-cut picture than depicted in media reports.

"The key takeaway is that gender is not a primary determinant of work-family conflict," Allen said. [7 Ways to Improve Your Work-Life Balance]

That doesn't mean men and women experience work-life-balance struggles the same way. In the study data, men worked more hours than women, and women were more likely to spend more time on family tasks, Shockley said. That should mean that men experience many more work intrusions on family, and that women experience many more family intrusions on work, she said. But because the analysis didn't see a stark difference in intrusions between the genders, something else may be going on. One possibility, Shockley said, is that women build stronger boundaries around work than men do, actively preventing overlap.

Or, she said, the kind of questions psychologists ask about work may not capture the full difference between men and women. For example, if women feel more guilt about their work-life conflicts than men do, it could have a real emotional effect — but one that wouldn't appear in the data. Shockley and her team plan to conduct studies in a laboratory environment in which men and women read about work-life conflicts and undergo physiological measurements, like blood pressure and heart rate, to see if one gender or the other gets more stressed.

Another possibility, Allen said, is that women get all the attention for work-life balance because they are more likely to talk about (and consume news about) their struggles than men are.

Discussing work-life balance as a women's issue may be selling both sides short, Shockley said. Employers may become more prone to thinking that women aren't committed to work and thus may hesitate to offer them jobs or promotions. Meanwhile, men could get shoehorned into a workaholic role they don't relish.

"Our data would suggest that men are struggling similarly to women in experiencing work-family conflict," Shockley said, "so the fact men aren't being talked about means they're missing out on some support."

Original article on Live Science. 

This article was originally published at The Conversation. The publication contributed the article to Live Science's Expert Voices: Op-Ed & Insights.

"I'm not bossy, I'm the boss."

So proclaims Beyoncé in a video in support of the #banbossy campaign. The campaign highlights how when little boys take charge, they're often praised for being a "leader." But when little girls do, they're more likely to be scolded for being too "bossy."

And it matters for grownups, too. Research and media stories abound with examples of how gender stereotypes disadvantage women leaders. A woman manager is less likely to be taken seriously by the people who work for her.

When men direct others, they're often assumed to be assertive and competent. But when women direct others, they're often disliked and labeled abrasive or bossy.

Our new study puts a twist on this narrative. Gender bias doesn't merely disadvantage women, it also can disadvantage men. The reason? We don't just stereotype men and women. We stereotype jobs.

Firefighters and nurses

Many jobs in the economy are gender-stereotyped. Firefighting is thought of as a man's job, whereas nursing is thought of as women's work.

Previous studies have shown that these stereotypes – which shape our expectations about whether a man or a woman is a better "fit" for a given job – are powerful because they can bias a whole host of employment outcomes. For instance, they influence the chances that a man or a woman will apply for the job, that he or she will be hired, the pay each would receive and even performance evaluations that determine promotions.

But how quickly do these gender stereotypes get attached to jobs in the first place? And, to what extent might such stereotypes affect the level of authority and respect that people are willing to give the man or woman who works in that job?

How a job gets stereotyped

To answer these questions, we studied a job that is ambiguously related to gender: a microfinance loan manager in Central America.

In this region, the microfinance loan manager job is new and gender-balanced in its composition. Unlike firefighters or nurses – jobs that are already strongly gender-stereotyped – loan managers at the microfinance bank we studied are about 50/50 men and women.

The nature of commercial microfinance makes managers' positions more gender-ambiguous. Microfinance is associated with the financial industry, which is traditionally masculine. But microfinance also has a legacy of social service and poverty alleviation, which are female-stereotyped activities.

Additionally, in the context we studied, the loan manager job had been around for less than 10 years, making it even less likely that clients would have strong preconceptions about whether it was a "man's job" or a "woman's job."

Loan managers at the bank we focused on are frequently reshuffled from one borrower to another. This quasi-random reshuffling allowed us to observe how borrowers' repayment patterns differed when they were paired with male and female loan managers. For example, a borrower might be paired with a male manager initially and then transferred to a female manager. This switching process allowed us to examine how clients' repayment rates varied when the only thing that changed was their managers' gender.

We examined borrowers' missed payment rates as a measure of the authority they afford their managers. Making a payment on time signals that the borrower views the manager as someone whose authority is legitimate and whose directives should be followed. In contrast, missing a payment signals that the borrower feels he or she can approach his or her responsibilities to the manager more laxly. When borrowers miss payments, it suggests the manager lacks the ability to secure compliance and therefore lacks authority.

We found that it took only one interaction before clients assigned a gender to the job and began to treat anyone in that role (man or woman) based on that stereotype, which meant less authority if the loan manager position was seen as a "woman's job." So if a client's first manager was a woman, they would tend to miss more payments on their loan – even if later transferred to a male manager – compared with one who was initially paired with a man. These effects persisted even when we accounted for other factors that might affect repayment, like income and loan size.

Male managers whose clients perceived the job as a "woman's job" experienced an especially large disadvantage compared to male managers whose clients perceived the job as a "man's job."

When men stepped in to work with a client who had initially worked with another male loan manager, the client was highly compliant with his directives. But when men stepped in to work with a client who had initially worked with a female loan manager, the client afforded them much less authority. They were much less compliant than they would have been if they had initially worked with a male loan manager.

Gendered jobs harm us all

When gender stereotypes get attached to a job, it biases the authority that people attribute to the man or woman who happens to work in that position. In this way, men experience negative bias when working in positions that others associate with women.

Our findings show that, when men work in a managerial job that people associate with a man and male stereotypes, they are able to wield a substantial amount of authority over clients. But when the very same managerial job happens to be associated with a woman, men who work in that position are viewed as significantly less legitimate sources of authority.

In other words, our study suggests that stereotyping a job as "women's work" and societal biases that grant women less authority than men harm us all.

Ideally, we want to live in a world where we perform the work that is best suited to our abilities and where an individual in a position of authority receives the same respect, regardless of gender. If we all can support both men and women who work in gender-atypical roles, perhaps we can become less likely to devalue some workers on the basis of arbitrary and old-fashioned gender stereotypes.

Sarah Thebaud, Associate Professor, Sociology, University of California, Santa Barbara and Laura Doering, Assistant Professor of Strategy and Organization, McGill University

This article was originally published on The Conversation. Read the original article.

President Donald Trump said today (July 26) that transgender individuals could not serve in the military.

"After consultation with my Generals and military experts, please be advised that the United States Government will not accept or allow … transgender individuals to serve in any capacity in the U.S. Military," Trump tweeted.

"Our military must be focused on decisive and overwhelming … victory and cannot be burdened with the tremendous medical costs and disruption that transgender in the military would entail," he continued in another tweet. [The 10 Most Outrageous Military Experiments]

A few thousand transgender people currently serve in the military, according to a 2016 report from researchers at the RAND Corporation. In June, the Trump administration delayed making a decision on whether to allow new recruits who are transgender to join the military, according to The New York Times.

Trump's announcement today goes against a policy enacted in June 2016 by the Obama administration, which allowed transgender individuals to openly serve in the military.

In that 2016 report from RAND, researchers led by senior political scientist Agnes Gereben Schaefer looked at the implications of having transgender individuals serve openly in the armed forces. The RAND Corporation is a nonprofit research organization that focuses on public policy. Here are five facts about transgender individuals in the military that the researchers found.

The total number of transgender individuals in the military is very low.

In 2014, there were an estimated 1,300 to 6,600 transgender individuals serving in the military, according to the RAND report.

That year, there were more than 1.3 million active service members, meaning that transgender individuals made up between 0.1 and 0.5 percent of the total active military, according to the report.

In the Selected Reserve (the non-active portion of the military), the RAND study estimated there were between 830 and 4,160 transgender individuals in 2014.

Not all transgender service members seek transition-related treatments.

A subset of the total number of transgender individuals in the military choose to engage in any type of procedures to transition to a gender that differs from the one they were assigned at birth, according to the RAND report. And even among those who choose to do so, the transition may be "primarily social" and involve no medical treatments.

When medical treatments are involved, they can include hormone therapy, hair removal and for some, surgery.

Transition-related treatment would disrupt less than 0.1 percent of the active military.

The RAND researchers estimated that between 29 and 129 active-duty transgender individuals would seek transition-related treatment that could disrupt their ability to deploy each year. This estimate represents less than 0.1 percent of the total number of people in the military.

In comparison, in 2015, approximately 50,000 active-duty military personnel, or 14 percent, in the Army alone were ineligible to deploy for various legal, medical or administrative reasons, according to the RAND report.

Gender transition-related health care costs are "relatively low."

Though Trump cites "tremendous medical costs" related to transgender individuals serving in the military, the RAND study estimated these costs would fall between $2.4 million and $8.4 million each year.

These costs would increase overall military health care spending by an "exceedingly small" amount, the report said. Between 0.04 and 0.13 percent of the approximately $6 billion spent in 2014 would go to transition-related health care costs, the researchers found.

Foreign militaries can offer insights.

In 2016, 18 countries allowed transgender individuals to serve openly in the military, according to the RAND report.

For their report, the researchers focused specifically on four countries — Australia, Canada, Israel and the United Kingdom — and found that none of these countries' militaries "reported a negative impact on the operational effectiveness, operational readiness or cohesion of the force."

Originally published on Live Science.

It's a childhood memory that many people may have: When Mom isn't home for dinner, Dad takes charge … and orders pizza. Or throws some hot dogs in the microwave. Either way, it's not a choice Mom approves of.

Now, a small new study shows that dads really do make less-healthy choices when feeding the family — and this can take a toll on moms.

Study author Priya Fielding-Singh, a doctoral candidate in sociology at Stanford University in California, said she was not surprised that the fathers in the study did less housework, including both "food work" and childcare, than mothers — indeed, national data has previously shown this unequal division of labor is common. But what was surprising in the new study was that dads' lack of involvement in feeding the family can really take a toll on moms, Fielding-Singh said. [10 Ways to Promote Kids' Healthy Eating Habits]

"Many dads are less invested in some of the healthy-eating priorities that moms really hold dear," and that can lead to more work, and more stress, for moms, Fielding-Singh told Live Science. And teens take note of these family dynamics, she added.

In the study, published online in June in the journal Appetite, Fielding-Singh interviewed 42 moms, 14 dads and 53 teens from more than 40 families in the San Francisco Bay Area and asked about family responsibilities when it came to family meals. All of the families were middle class or upper-middle class.

Fielding-Singh found that in 41 of the 44 families included in the study, the family members agreed that Dad's eating habits were less healthy than Mom's. It wasn't just that the moms considered themselves healthier than their husbands, Fielding-Singh noted: The dads agreed.

Set dynamics?

Though some of the moms in the study said they were happy to do most of the work required to feed the family, other moms said they wanted the dads to do more, such as grocery shopping and cooking, Fielding-Singh said.

But there was a catch: Moms felt that if they let dads do these tasks, the food would end up being less healthy, Fielding-Singh said. So, by letting dads more to do, moms felt like they were being worse caregivers to their children. This, in turn, made moms feel guilty — so they kept doing most of the tasks themselves, instead of delegating them to dads.

"Even though some moms were unhappy with it, few saw that there could be an alternative," Fielding-Singh said. "There was definitely a resignation" on the part of moms, she added.

Some of that resignation may stem from deeply embedded gender roles.  

"Feeding families is very central to motherhood," she said. "We hold mothers accountable for the foods that families eat." Mothers often judge themselves, and other moms, by how well they feed their families, she noted.

Dads, on the other hand, aren't usually seen as being responsible for feeding the family, Fielding-Singh said. Instead, fathers have typically been judged by how well they support their families financially and more recently, how involved they are in children's lives. But getting kids to eat healthy? That didn't factor in as an important part of being a father, she said. [History's 12 Most Doting Dads]

"It's not that the husbands were trying to be unfair to their wives" by not taking on the responsibilities of food work, she said. Dads weren't trying to hurt their kids diets or make the moms' lives harder, for example. "They simply didn't see it as their responsibility to be making sure that kids were eating healthy — they saw it as Mom's responsibility." And moms, she added, also saw it as Mom's responsibility.

But it's possible that this division of labor between husbands and wives wasn't always present in the couples' relationship. As a part of her interviews, Fielding-Singh said that she asked parents what changed about the way they approached food once they had kids. "What was striking," she said, was that "almost every mother" said things changed after she had kids, but the responses were more mixed among dads. In other words, many women seemed to become more concerned about the healthiness of food, rather than the men getting less concerned.

That means that it's possible things were more equal before kids came into the picture, Fielding-Singh said. But "because feeding is so gendered, it's almost as if this dynamic was created whereby mothers instantly cared more" once they had children.

Teens take note

The division of labor between Mom and Dad didn't just affect their own relationships; these differences in approaches to feeding the family also stood out to parents' teenage children, the study found. [10 Facts Every Parent Should Know About Their Teen's Brain]

The teens interviewed "very clearly understood and articulated that their parents had different priorities around healthy eating," Fielding-Singh said.

This divided approach is notable because kids could view their parents as a united front or solid unit, Fielding-Singh said. For example, teens might say, "my parents"care about my education — but this is not the case with food. Instead, teens might say, "my mom" cares about eating healthy, but "my dad" doesn't.

One of the reasons this matters, Fielding-Singh noted, is that teens observe their parents, and they learn how to behave, in part, from what they see their parents do. And in the study, many daughters watched their moms do the food work and the health work, and many sons watched their dads, and saw that their dads left the work to their moms, she said.

The fact that teens picked up on this "so clearly" means that "there's a real possibility that this one of the ways gender norms are transmitted," Fielding-Singh said.

Originally published on Live Science.

Men can't nurse babies, so why on Earth do they have nipples?

The answer has to do with how humans develop in the womb, said Ian Tattersall, a paleoanthropologist at the American Museum of Natural History in New York City.

"Basically, males and females are all built from the same genetic blueprint," Tattersall told Live Science. "Then, [they] develop in slightly different directions [in utero and] particularly after we hit puberty." 

Related: Men vs. Women: Our Key Physical Differences Explained

During the first several weeks, male and female embryos follow the same blueprint, which includes the development of nipples. However, at about six to seven weeks of gestation, a gene on the Y chromosome induces changes that lead to the development of the testes, the organ that makes and stores sperm and produces testosterone, according to the book "Exploring the Biological Contributions to Human Health: Does Sex Matter?" (National Academies Press, 2001).

After the testes are formed, the male fetus begins producing testosterone at about nine weeks of gestation, changing the genetic activity of cells in the genitals and brain. But by then, those nipples aren't going anywhere.

Human development explains why males have nipples. But why do men keep this vestigial structure? (A vestigial body part does not serve an evolutionary purpose.)

For starters, having nipples isn't detrimental for males. "There's no real metabolic cost to having nipples," Tattersall said.

Furthermore, just because men don't need nipples, it's not exactly an evolutionary priority to get rid of them.

"The fact is that we carry a lot of evolutionary baggage around with us," Tattersall said. "Natural selection is not hovering there all of the time to get rid of things we absolutely don't need."

Additional reporting by Live Science contributor Ben Mauk.

The recent case of man in a powerful position making a sexist comment — during a company meeting aimed partly at addressing discrimination against women — raises the question of why gender issues in the workplace are so difficult to quash.

During an Uber staff meeting on June 13, board member Arianna Huffington said that having one woman on a company's board often leads to more women joining the board.

David Bonderman responded, "Actually, what it shows is that it's much more likely to be more talking," according to The New York Times.

Bonderman resigned from the board that evening, and said in a statement that he understood "the destructive effect" his comments had, according to The New York Times. [6 Ways Sexual Harassment Damages Women's Health]

Though he apologized, it seems unclear to many how Bonderman could have made such a comment. Many people don't understand what sexism actually is, said Philip Cohen, a professor of sociology at the University of Maryland.

"It's amazing how often men are surprised to hear that their remarks are interpreted as sexist," Cohen told Live Science. One reason men may not realize that a remark is sexist is that they're not "properly socialized," Cohen said. That is, they may work in a very segregated work environment, for example, or they're just not aware of how women experience that same working environment.

This surprise — that someone took a man's comment to be sexist — can often turn into defensiveness and resentment, Cohen said.

And fixing the problem goes far beyond simply addressing the comment. There's a need to address the underlying issues of power and inequality that give rise to this sort of behavior in the first place, said C.J. Pascoe, an associate professor of sociology at the University of Oregon.

Companies don't talk about things such as masculinity and the role it plays in gender inequality, Pascoe told Live Science. But dominance over women is a "central part of the contemporary understanding of masculinity," and that extends beyond the workplace, she said.

"This is something that's threaded throughout a society, and that isn't limited to any one company or one school or any one family," Pascoe said. 

In Western cultures, masculinity is predicated on dominance, both in terms of men dominating other men and dominating women, Pascoe said. Part of what men are doing when they talk over women, interrupt women or make sexist jokes is exercising their dominance over women to "prove" their own masculinity.

Pascoe noted that this understanding of masculinity isn't limited to older men; there's evidence that younger men think this way too. Although younger men and teens may have learned to avoid expressing sexist ideas in front of women, they haven't necessarily changed their perspective on sexist jokes, she said. "I'm not sure that's a sign of success," she added. [Busted! 6 Gender Myths in the Bedroom and Beyond]

Addressing the issue

It's become more common for people who witness events like what happened at the Uber meeting to bring shame on the offender, Cohen said. And though this can be useful for highlighting a problem, "it might not be as corrective as it feels," he said. Instead, it could just drive the problem underground, he said.

In many cases, companies respond to incidents like the one at Uber by holding a workshop or requiring people take an online training course, Cohen said. But research shows that these measures don't work unless they're coupled with concrete measures with identifiable actions to reduce sexism, and unless people in positions of authority are held accountable for carrying out these measures.

Pascoe noted that online training courses often focus on one thing: sexual harassment. Companies could instead focus on training people to recognize the ways that men exercise dominance over women, and show how to avoid that, she said. For example, training could include data on how men interrupt women more than men interrupt men, and how men talk more than women do in mixed-gender groups.

Companies should take a step back when thinking about workplace training and avoid focusing on just one type of bad action. Instead, they should "think about how gender inequality weaves itself throughout our relationships and think about ways that we could combat that," Pascoe said.

Be concrete

Cohen stressed that it's important that companies set clear goals to eliminate workplace inequality and communicate that those goals are important. "You can't just react when something unpleasant happens and expect the climate to change," he said. [5 Misconceptions About Sexual Assault]

One way a company can show that it is really behind a goal is to include that goal in performance evaluations of managers and executives. In some cases, people don't make the connection that something they do or say could be sexist, or it's just not taken seriously, Cohen added.

Of course, each company faces unique challenges, Cohen said. It's hard to address the issue of sexism in the workplace in a blanket way, but the "bottom line is you've got to be specific and you have to hold people accountable for meeting objective goals."  For a company with a track record of problems like Uber, that might mean setting a goal of having no reports of sexism for six months or people will be fired, he said.

Despite the increased attention that sexist incidents have gained in the media and cultural environment in recent years, Cohen noted that gender equality trends are not very favorable at the moment. Rather, there are indicators that things are stalling in this area.

Though companies may be embarrassed by these incidents and feel like they have to react, the underlying culture doesn't change, Cohen said.

Originally published on Live Science.

Products aimed at regrowing hair cost more when they are marketed to women than when they are marketed to men, a new study finds.

Researchers found, for example, that one popular product, Rogaine, cost 40 percent more when it was marketed to woman than when it was marketed to men. One foaming Rogaine product marketed to women cost $11.27 per 30 milliliters (mL), but a product of the same strength and with the same ingredients that was marketed to men cost $8.05 per 30 mL.

This isn't the first time that researchers have uncovered gender-based price differences for consumer products. Indeed, this price mark-up practice for products marketed to women has a name: the "pink tax," said study co-author Dr. Jules Lipoff, an assistant professor of dermatology at the University of Pennsylvania. [7 Bizarre Drug Side Effects]

But in the case of hair-loss products, the product involved contains a medication, called minoxidil. This phenomenon — of gender-based price differences in medications — has not been reported before, Lipoff told Live Science.

In the new study, published June 7 in the journal JAMA Dermatology, researchers looked at hair-loss products sold at 24 national chain pharmacies — including CVS, Kroger, Rite Aid, Target, Walgreens and Walmart — in four states: Pennsylvania, New York, Ohio and Indiana. The researchers examined the prices, compositions and other information related to a total of 41 products. All of the products contained minoxidil, an over-the-counter topical medication approved for treating hair loss. The researchers looked at a total of 14 products marketed to women and 27 products for men.

In the study, the researchers considered that different products contained different concentrations of minoxidil.

In one part of the study, the researchers compared the prices of "extra-strength" products sold to men with the prices of "regular-strength" products sold to women. In both cases, the products were to be applied twice daily. They found that the prices of these two types of product were almost the same: about $7.60 per 30 mL, on average, even though the "extra-strength" product contained 5-percent minoxidil and the "regular-strength" product contained 2-percent minoxidil.

In other words, women were being asked to pay the same amount for a product that contained a lower concentration of minoxidil.

And when the researchers looked at the prices of products that contained equal concentrations of minoxidil, they found that those marketed to women were significantly more expensive.

In this case, the products in question were a 5-percent minoxidil Rogaine foam product marketed to men and 5-percent minoxidil Rogaine foam products marketed to women. For men, the 5-percent solution was to be applied twice daily, and for women, the 5-percent solution was to be applied once daily.

All in all, the products marketed to women were about 40 percent more expensive than those that were marketed to men, they concluded. [Busted! 6 Gender Myths in the Bedroom & Beyond]

This means that "Although women use minoxidil foam once daily compared with twice daily for men, the group of people (women) who require the same medication less often are paying more for each dose," the researchers wrote.

Even though there may be differences in the costs of testing the product, submitting it for approval and marketing it to women versus men, "it remains that women are paying significantly more than men for an identical medication," the researchers wrote.

There is, however, a simple way for women to overcome this issue, Lipoff said.

"There is nothing that restricts women from just buying the other product," he said. "I can say as a general rule, when I think Rogaine for women would be indicated, I have no hesitation in telling them to use the Rogaine for men." 

Marc Boston, a spokesperson for Johnson & Johnson, the makers of Rogaine, said that the price of its Unscented Foam product, which contains 5-percent minoxidil, is the same for the men's version as it is for the women's version. "Both men's Rogaine Unscented Foam and women's Rogaine Unscented Foam are priced the same when sold in the same size volume, can for can, both on our Rogaine brand retail web page and when we sell to retailers," Boston told Live Science in an email. 

In the study, the researchers focused on prices at retail stores. They did not include Rogaine's website in their analysis.

Originally published on Live Science.

Trouble sleeping may take a bigger toll on women than on men, a new study from Australia finds.

Women in the study were more likely than men to have sleep disorders that made them feel tired during the day, the researchers found. And women were also more likely to have trouble with memory and concentration due to sleepiness.

"We found that females were more likely to have sleeping disorders associated with daytime sleepiness," study co-author Dr. John Malouf, the founder of the SleepGP sleep clinic in Coolangatta, Australia, said in a statement. "Females were also likely to feel more affected by the burden of their symptoms." [5 Surprising Sleep Discoveries]

In the study, which was published in May in the Journal of Clinical Sleep Medicine, the researchers looked at data on nearly 750 adults in Australia who had sought medical care for sleep problems between April 2013 and January 2015. At the time, the people filled out questionnaires about their sleep and overall health.

For example, the questionnaires asked if the people ever had trouble falling asleep and if they felt excessively tired or sleepy during the day. One question asked if the people had trouble concentrating during the day because of sleepiness. In addition, the researchers wanted to know if the participants or their partners snored.

One-third of all people in the study said that they had trouble falling asleep at night, though this was more common among the women than the men. Nearly half of the women reported problems falling asleep, compared with just 27 percent of men.

The women in the study also reported more problems during the day as a result of their sleep problems at night.

For example, nearly half of the women in the study, 49 percent, said they had sleep problems that caused daytime sleepiness, while 37 percent of the men in the study said the same. The researchers also found that 77 percent of the women felt excessively sleepy or tired during the day, compared with 66 percent of the men.

Daytime sleepiness had a significant effect on the women's ability to concentrate during the day; 89 percent of the women said they had trouble concentrating because they were tired, compared with 74 percent of men. And 80 percent of women said that being sleepy led to memory problems, compared with 58 percent of men, the study found. [7 Strange Facts About Insomnia]

The reasons behind these differences between the sexes are unclear, and more research is needed to explore possible reasons, the researchers said. However, previous studies have suggested that hormonal factors as well as anatomical and physiological differences between men and women may play a role, the study said.

Women in the study also seemed to be more affected by their partners' snoring, the research said. Snoring men were more likely to keep their partners awake than snoring women were.

This was particularly apparent when the researchers asked the participants if their snoring had ever forced their partners out of the bedroom. The scientists found that 63 percent of the men who said their snoring kept their partners awake also said that the snoring forced their partners the room; 54 percent of the women who said their snoring kept their partners awake also said that the snoring forced their partners out of the room.

Though the reasons behind the findings on snoring are unclear, it is possible that women are simply more sensitive to their partners' snoring and men have a higher tolerance for their partners' snoring, the researchers said.

Originally published on Live Science.

The number of surgeries done to confirm a person's gender identity, also referred to as sex reassignment surgeries, has increased in recent years, according to the first report on the topic from the American Society of Plastic Surgeons (ASPS).

In 2016, more than 3,200 gender-confirmation surgeries were performed in the U.S., according to the report. That's up 20 percent from the number performed in 2015, the ASPS said. The organization began collecting data on gender-confirmation surgeries in 2015.

Gender-confirmation surgeries include any type of surgery that people undergo to make their physical characteristics better align with their gender identity. This could include anything from facial and body contouring to genital reconstruction surgery, according to the ASPS.

It's important to note that the steps people may undergo to transition to the gender that aligns with their identity vary depending on the person, according to GLAAD. Not all transgender people choose to undergo surgery as part of their transition. (GLAAD is the group formerly known as the Gay and Lesbian Alliance Against Defamation.)

"There is no one-size-fits-all approach to gender confirmation," Dr. Loren Schechter, a board-certified plastic surgeon in Chicago who performs gender-confirmation surgeries, said in a statement from the ASPS. [10 Milestones in Gay Rights History]

The recent rise in surgeries may be related to better access to care for transgender patients, he said.

"In the past several years, the number of transgender patients I've seen has grown exponentially," Schechter said. "Access to care has allowed more people to explore their options, and more doctors understand the needs of transgender patients."

Until recently, private insurance companies treated transgender-related medical procedures as cosmetic, and specifically excluded these medical procedures from their coverage, according to GLAAD. But in 2016, the Department of Health and Human Services ruled that this practice was illegal, and insurance companies that receive federal funds are now required to cover services for transgender people if those services are covered for non-transgender people, according to the National Center for Transgender Equality.

Still, although this ruling improved access to health care for transgender people, insurances that do not receive federal funds could still discriminate and deny services for transgender people, according to GLAAD.

"For transgender people...surgical options are a corrective treatment, not cosmetic," Gearah Goldstein, a patient of Schechter's who underwent gender-confirmation surgery, said in the statement. "The types of surgeries someone has is very personal and private, and you wouldn't even know someone had surgery if you saw them walking down the street. It's not about how we're perceived by the public, but how we perceive ourselves," Goldstein said.

Schechter said he often works with other doctors to provide care for transgender patients. "It takes a team of experts across different disciplines working together to provide comprehensive care," Schechter said.

Original article on Live Science.

Estrogens are hormones that are important for sexual and reproductive development, mainly in women. They are also referred to as female sex hormones. The term "estrogen" refers to all of the chemically similar hormones in this group, which are estrone, estradiol (primary in women of reproductive age) and estriol. 

Estrogen's function

In women, estrogen is produced mainly in the ovaries. Ovaries are grape-sized glands located by the uterus and are part of the endocrine system.

Estrogen is also produced by fat cells and the adrenal gland. At the onset of puberty, estrogen plays a role in the development of so-called female secondary sex characteristics, such as breasts, wider hips, pubic hair and armpit hair.  

Estrogen also helps regulate the menstrual cycle, controlling the growth of the uterine lining during the first part of the cycle. If the woman's egg is not fertilized, estrogen levels decrease sharply and menstruation begins. If the egg is fertilized, estrogen works with progesterone, another hormone, to stop ovulation during pregnancy.

During pregnancy, the placenta produces estrogen, specifically the hormone estriol. Estrogen controls lactation and other changes in the breasts, including at adolescence and during pregnancy. 

Estrogen is instrumental in bone formation, working with vitamin D, calcium and other hormones to effectively break down and rebuild bones according to the body's natural processes. As estrogen levels start to decline in middle age, the process of rebuilding bones slows, with postmenopausal women eventually breaking down more bone than they produce. This is why postmenopausal women are four times more likely to suffer from osteoporosis than men, according to the Cleveland Clinic.

Estrogen also plays a role in blood clotting, maintaining the strength and thickness of the vaginal wall and the urethral lining, vaginal lubrication and a host of other bodily functions.

It even affects skin, hair, mucous membranes and the pelvic muscles, according to Johns Hopkins Medicine. For example, estrogen can make the skin darker. Some researchers hope to use this information to create safe fake tanning lotions by activating the skin darkening reaction in estrogen, without triggering other changes in the body due to the hormone.

"If you expose melanocytes to estrogen, they respond by making more melanin, but they don't have the classic estrogen receptor," Dr. Todd Ridky, senior author of a 2016 study on estrogen and skin color and an assistant professor of dermatology at the University of Pennsylvania.

The hormone also affects the brain, and studies also show that chronically low estrogen levels are linked with a reduced mood, according to the National Library of Medicine.

Men produce estrogen as well, but at lower levels than women. Estrogen in males is secreted by the adrenal glands and by the testes. In men, estrogen is thought to affect sperm count. Overweight men are more commonly affected by low sperm count due to estrogen because there is more adipose tissue in the obese, which can set off the creation of excess estrogen, according to a 2010 paper published in the Asian Journal of Andrology. 

In 2011, researchers at American University in Washington, D.C., found a link between estrogen and the ability to control excessive inflammation in the brain. This research is hoped to help those with neurodegenerative disorders such as Parkinson's disease.

Estrogen can also help with ovarian cysts. "Most of the time nothing needs to be done to treat or prevent functional cysts," said Dr. Antonella Lavelanet, an obstetrician at Boston Medical Center. "However, for women who are prone to ovarian cysts, an estrogen-containing birth control may help reduce the risk of developing certain types of functional cysts, in particular cysts that occur after ovulation. Oral contraception pills and the patch or ring, which have similar mechanisms of action, can help suppress ovulation."

Changes in estrogen levels

There are many times throughout a person's life when estrogen levels may change. For example, estrogen levels naturally increase during puberty and during pregnancy. Estrogen levels fall after menopause, or when a woman stops menstruating. This reduction in estrogen production can cause symptoms such as hot flashes, vaginal dryness and loss of sex drive. Estrogen levels also decrease after childbirth.

Other conditions that can cause estrogen levels to drop include hypogonadism (or diminished function of the ovaries) and polycystic ovarian syndrome. Extreme exercise and anorexia can also cause a decrease in estrogen levels because women with low body fat may not be able to produce adequate amounts of estrogen.

Some postmenopausal women with nonalcoholic fatty liver disease (NAFLD) have long durations of estrogen deficiency. Recent research has found that this deficiency could increase the risk of having more severe fibrosis, according to a study published in the journal Hepatology.

Medications with estrogen

Estrogen is found in most oral birth control pills (along with the hormone progestin.) Estrogen helps stop ovulation during pregnancy, and birth control pills mimic this effect by regulating the levels of estrogen and thereby preventing ovulation from occurring.

Hormone replacement therapy — a treatment to reduce symptoms of menopause — also includes estrogen (which can be given in combination with progestin). This therapy is sometimes used to treat postmenopausal problems such as hot flashes, night sweats, anxiety, sleeping problems and vaginal atrophy, a thinning, drying and inflammation of the vaginal walls due to a decrease in estrogen, according to the U.S. National Library of Medicine.

Estrogen hormone replacement therapy is also key for transgender women to achieve breast growth, inhibit body hair growth and to create other changes that are important for transitioning from male to female. Hormone administration that uses estrogens and androgens has been used for over 50 years as an effective in treatment for gender dysphoria, according to the University of California. Sublingual, transdermal and injectable estrogen hormones are preferable for the treatment of transwomen and may be combined with other drugs such as anesthetics for hair removal, anti-androgens and progesterone.

Estrogen side effects

While there are many benefits to estrogen, it can be a bad thing in some cases. For example, elevated estrogen levels may cause an increased risk for injury. A 2016 study published in the journal Medicine & Science in Sports & Exercise found that the risk of ligament injury may be mitigated by the use of oral contraceptives.

The majority of breast cancers are also sensitive to estrogen, meaning that estrogen promotes tumor growth. These cancers are called hormone receptor positive breast cancers. For people with these cancers, treatments to lower estrogen levels or block estrogen production can be used to help prevent cancer recurrence after surgery, or to slow cancer growth.

According to Breast Cancer.org, alcohol can increase a woman's risk of hormone-receptor-positive breast cancer. Alcohol also enhances the effects of estrogen in driving the growth of breast cancer cells, according to 2016 research at the University of Houston.

Endometriosis is another estrogen-dependent disease. Reducing estrogen levels and providing non-estrogen treatments have all been considered for the treatment of endometriosis. The problem is that reducing the levels of estrogen in women can lead to infertility. 

A study by the Women's Health Initiative showed that hormone replacement therapy — both solely estrogen and estrogen-and-progestin — had significant risks. It increased the risk of breast cancer, stroke and blood clots and did not, as predicted, lower the risk of heart disease. Given the danger, hormone replacement therapy should be prescribed on a case-by-case basis. It is currently approved for postmenopausal symptoms, though women who do start hormone replacement therapy are encouraged to try the smallest dose for the shortest amount of time, according to the Food and Drug Administration. Only women with a severe risk of osteoporosis who cannot take non-estrogen therapies should be considered for using hormone replacement therapy preventatively.

Live Science Contributor Jessie Szalay and staff writer Rachael Rettner contributed to this article.

Additional resources

• Tulane University: Estrogen
• Carleton College: Gender transition hormones
• National Blood Clot Alliance: Blood clots

Just because a judge makes it to the Supreme Court, that doesn't mean the person gets to speak freely: A new study finds that female justices are interrupted more than male justices.

This happens even though female justices on the Supreme Court speak less than their male colleagues, according to the study, which will be published in an upcoming issue of the Virginia Law Review journal.

In the study, the researchers analyzed transcripts of court proceedings during three Supreme Court terms: 1990, 2002 and 2015. The researchers tallied up the interruptions that took place when lawyers were presenting their cases to the court, a process called oral arguments. [8 Supreme Court Decisions That Changed US Families]

In 1990, there was only one woman on the Supreme Court: Justice Sandra Day O'Connor. In 2002, Justice Ruth Bader Ginsburg was on the bench alongside Justice O'Connor. Finally, in 2015, there were three female Justices: Justice Ginsburg, Justice Sonia Sotomayor and Justice Elena Kagan.

The researchers found that, overall, the female justices were interrupted about three times more often than their male counterparts.

For example, in 2015, Justice Sotomayor was interrupted 60 times and Justice Kagan was interrupted 54 times, whereas Chief Justice John Roberts was interrupted 27 times and Justice Antonin Scalia was interrupted just 19 times.

The interruptions took on many forms, said study authors Tonja Jacobi, a law professor at Northwestern University Pritzker School of Law in Chicago, and Dylan Schweers, a law student at the same institution. For example, during a 2015 oral argument, Justice Anthony Kennedy interrupted Justice Ginsburg, and though he acknowledged that he was interrupting, he kept going.

In other instances, male justices interrupted female justices to "mansplain," the researchers wrote. That is, the men either unnecessarily explained something to a female justice or explained to a third party what a woman was "trying to say," the study said.

The authors highlighted a 2002 instance in which Justice Kennedy interrupted Justice O'Connor and proceeded to "mansplain" to a lawyer by explaining a question O'Connor had asked perfectly clearly.

But male justices weren't the only ones who interrupted the female justices on the court: The researchers found that lawyers also interrupted the court's women. This is surprising, because lawyers are not allowed to interrupt justices, and the chief justice is supposed to intervene when this occurs, the researchers noted.

The researchers highlighted a 2002 instance in which Chief Justice William Rehnquist did, in fact, intervene when a lawyer interrupted Justice Scalia. But in different case, Justice Rehnquist did not intervene when a lawyer interrupted Justice Ginsburg.

But gender wasn't the only factor that played a role in interruptions, the researchers found. A justice's ideology also appeared to have an effect, the researchers found, with conservative justices interrupting liberal justices more often than the reverse occurred. However, the researchers noted out that it was difficult to disentangle the effects of gender and ideology, as the three female justices on the court in 2015 were all liberal.

Seniority also played a role, as more-senior justices were more likely to interrupt less-senior justices, the study said. However, this effect was smaller than that of gender and ideology, according to the study.

Originally published on Live Science.

American teens have no problem with gender equality in the workplace, but home life is a different story.

A new report released today (March 31) by the Council on Contemporary Families (CCF) finds that modern high school seniors increasingly believe that everyone is better off if the man is the achiever outside the home while the woman takes care of domestic duties. In 1992, 58 percent of high school seniors disagreed that male-breadwinner arrangements were best. By 2014, the most recent year that survey data are available, that number had slipped to 42 percent.

"It's been a steady reversal," said study co-author Joanna Pepin, a doctoral candidate in sociology at the University of Maryland. [Top 12 Warrior Moms in History]

A complex relationship with gender

The findings reveal a complicated approach toward gender among the youngest millennials. They are based on repeated surveys of each year's high school seniors called the Monitoring the Future Project. Each year since 1975, a sample of seniors has answered the same questions, allowing comparisons between age cohorts.

Since the 1970s, large majorities of high school seniors have supported egalitarian workplaces: In 1976, 82 percent of seniors said women should be considered just as seriously as men in executive jobs and in politics. By 1994, agreement with that belief hit 91 percent, where it has stayed strong. Likewise, agreement that women should have the same job opportunities as men started at 76 percent in 1976 and rose to 89 percent by 1994, staying stable thereafter. Attitudes toward working mothers have also steadily improved.

And yet, when asked about the domestic sphere, high school seniors became more egalitarian between 1976 and 1994 — and then started to slide in the other direction. In the same way as acceptance of the male-breadwinner model re-emerged after 1994, so did the notion of men as the head of the family. In 1976, 59 percent of high school seniors disagreed that men should make all the important decisions in the family. That disagreement peaked at 71 percent in 1994 and steadily eroded to 63 percent by 2014. [I Don't: 5 Myths About Marriage]

"We were really surprised to see this," Pepin told Live Science, because youth are typically thought of as more progressive than their elders.

Nika Fate-Dixon, a researcher at the Evergreen State College in Washington, analyzed data in an accompanying report for the Council on Contemporary Families and found that the picture is complex among 18-to-25-year-olds as well. Another long-running questionnaire, the General Social Survey, asks adults some of the same questions as youth are asked in the Monitoring the Future surveys. Since 1997, adults of all ages have increasingly disagreed that male-breadwinner families are best (70 percent of all adult women now disagree with that statement, as well as nearly 70 percent of men), that study showed.

However, when age was considered, the scientists found that 18-to-25-year-olds have similar ambivalence about gender roles as high school seniors, with some declines in positive attitudes toward mothers working outside the home. In addition, the percentage of people in this age group disagreeing that male breadwinners are best declined from 84 percent in 1994 to 75 percent in 2014.

More questions than answers

Much of the declining interest in gender egalitarianism at home came from men in the 18-to-25-year-old surveys, Fate-Dixon said. That wasn't the case for the high school seniors, though: Men have always been a bit less supportive than women of egalitarianism, but that gap hasn't grown, Pepin and co-author David Cotter of Union College in New York reported. Likewise, black youth have always been more egalitarian than white youth, but support has declined similarly among all races.

Pepin and Cotter suspect that young millennials have landed on an approach to gender that they call "egalitarian essentialism." The schism between egalitarianism in public life and traditionalism in private seems to suggest that youth believe men and women should be treated equally, but that their essential natures are inherently different from one another, Pepin said. [6 Scientific Tips for a Successful Marriage]

Dan Carlson, a sociologist at the University of Utah who wrote a response to Pepin and Cotter's report for the CCF, called this attitude the "supermom strategy."

"If you want to work, fine, but you can't skirt these traditional responsibilities at home," Carlson said, describing how youth accept working women if they're also taking on the brunt of domestic chores. Carlson argues that the root of these beliefs may be lack of supportive policies for families in the United States. High school seniors may see their parents struggling to achieve egalitarian relationships in an environment where paid maternity leave is rare and paid paternity leave is even rarer. A Pew Research Survey released March 23 found that only 14 percent of civilian workers in the United States had access to paid family leave. A second Pew study released March 27 found that of men who had taken parental leave (paid or unpaid) in the past two years, the median length of leave was one week (compared with 11 weeks for mothers).

"A lot of couples are forced into conventional arrangements" by the high cost of child care and lack of paid leave, Carlson told Live Science. "It would seem that children are taking cues from their parents in this regard and saying, 'Maybe a traditional setup at home is just better for everybody as opposed to trying to fight this tide.'"

Carlson's earlier research has also found that while many couples would prefer egalitarian relationships, a lot of working-class couples are seeing declines in men's employment opportunities and are being forced into female-breadwinner roles that they don't necessarily prefer.

"We're finding that families are having a hard time adapting to that," Carlson said.

Pepin agreed that lack of family support is "definitely not helping" to change gender attitudes. But economic pressure and workplace problems probably don't explain the whole decline in support of egalitarianism, she said. If working-class youth see their fathers struggling to pay the bills alone, she said, they might be more likely to value wages brought in by their mothers. Also, egalitarian relationships are valued by couples (a 2016 Pew Research Survey found that 56 percent say sharing chores is important to a successful marriage), and sociologists have found that egalitarian couples have the highest relationship satisfaction, Pepin said.

"Even though it's hard [to be egalitarian], it's getting easier," she said. "That is hard to reconcile" with backsliding egalitarianism among youth.

Even as they struggle to unravel why today's youth might not support gender equality at home and at work, sociologists aren't sure whether these attitudes will change with time. Today's high school seniors are much further from marriage and childbearing than the high school seniors of 1976, Carlson said — many might not marry for a decade or more. It's possible that their attitudes might change as they move through life.

"They might change their tune because they actually see what this all means, what a traditional relationship really portends and what egalitarianism really promises," Carlson said.

Original article on Live Science. 

This article was originally published at The Conversation. The publication contributed the article to Live Science's Expert Voices: Op-Ed & Insights.

How can modern parents raise the next generation to be free from corrosive gender and racial stereotypes? By the time children start elementary school, gender and race shape their lives in many ways that parents might want to prevent. As early as first grade, girls are less likely than boys to think members of their own gender are "really, really smart." And by just age three, white children in the United States implicitly endorse stereotypes that African-American faces are angrier than white faces.

These stereotypes go deeper than children's beliefs – they can also shape a child's behavior. By age 6, girls are less likely than boys to choose activities that seem to require them to be really smart, which could contribute to the development of long-term gender differences in science and math achievement.

Why do stereotypes develop in such young children? As a professor of early cognitive and social development, I have seen my research reveal how surprisingly subtle features of language contribute to a child's tendency to view the world through the lens of social stereotypes.

The problem of generalization

Many parents try to prevent the development of stereotypes in children by avoiding saying things like, "boys are good at math," or "girls cannot be leaders." Instead, parents might take care to say things that are positive, like "girls can be anything they want."

But our research has found that, to the developing mind, even these positive statements can have negative consequences.

For young children, how we speak is often more important than what we say. Generalizations, even if they say only things that are positive or neutral, such as "Girls can be anything they want," "Hispanics live in the Bronx" or "Muslims eat different foods," communicate that we can tell what someone is like just by knowing her gender, ethnicity or religion.

In our research, published in Child Development, we found that hearing generalizations led children as young as two years old to assume that groups mark stable and important differences between individual people.

In this study, children were introduced to a new, made-up way of categorizing people: "Zarpies." If they only heard statements about specific individuals, (e.g., "These Zarpies whisper when they talk"), children continued to treat the people as individuals, even though they were all marked by the same label and wore similar clothes. But if they heard the same information as a generalization (e.g., "Zarpies whisper when they talk"), they started to think that "Zarpies" are very different from everyone else. Hearing generalizations led children to think that being a member of the group determined what the members would be like.

In another recent study, we found that hearing these types of generalizations – even if none of them was negative – led five-year-old children to share fewer resources (in this case, colorful stickers) with members outside their own social group.

These findings show that hearing generalizations, even positive or neutral ones, contributes to the tendency to view the world through the lens of social stereotypes. It is the form of the sentence, not exactly what it says, that matters to young children.

From groups to individuals

Our research means that generalizations are problematic even if children do not understand them.

If a young child overhears, "Muslims are terrorists," the child might not know what it means to be a Muslim or a terrorist. But the child can still learn something problematic – that Muslims, whoever they are, are a distinct kind of person. That it is possible to make assumptions about what someone is like just by knowing if they are Muslim or not.

Language that uses specifics – instead of making general claims – avoids these problems. Sentences like, "Her family is Hispanic and lives in the Bronx," "This Muslim family eats different foods," "Those girls are great at math," "You can be anything you want," all avoid making general claims about groups.

Using specific language can also teach children to challenge their own and others' generalizations. My three-year-old recently announced that "Boys play guitar," despite knowing many female guitar players. This troubled me, not because it matters very much what he thinks about guitar playing, but because this way of talking means that he is starting to think that gender determines what a person can do.

But there is a very easy and natural way to respond to statements like these, which our research suggests reduces stereotyping. Simply say, "Oh? Who are you thinking of? Who did you see play the guitar?" Children usually have someone in mind. "Yes, that man at the restaurant played the guitar tonight. And yes, so does Grandpa." This response guides children to think in terms of individuals, instead of groups.

This approach works for more sensitive generalizations too – things a child might say, like "Big boys are mean," or "Muslims wear funny clothes." Parents can ask children who they are thinking of and discuss whatever specific incident they have in mind. Sometimes children speak this way because they are testing out whether drawing a generalization is sensible. By bringing them back to the specific incident, we communicate to them that it is not.

Every interaction counts

How much can this small change in language really matter? Parents, teachers and other caring adults cannot control everything that children hear, and exposure to explicitly racist, sexist or xenophobic ideas can also influence a child's view of societal norms and values.

But children develop their sense of the world through minute-by-minute conversations with important adults in their lives. These adults have powerful platforms with their children. As parents and caregivers, we can use our language carefully to help children learn to view themselves and others as individuals, free to choose their own paths. With our language, we can help children develop habits of mind that challenge, rather than endorse, stereotyped views of the people around us.

Marjorie Rhodes, Associate Professor of Psychology, New York University

This article was originally published on The Conversation. Read the original article.

Gender differences

Men and women can experience depression in different ways, and although they also share many common signs and symptoms, a better understanding of the differences may help those with depression, researchers say.

"We have known about sex differences for years when it comes to depression, and they are absolutely essential to understanding the illness," said Jill Goldstein, director of research at the Connors Center for Women's Health and Gender Biology at Brigham and Women's Hospital in Boston.

In one of the largest depression-related differences between the sexes, women have about twice the risk of developing the condition as men, Goldstein said. This results in part from biological reasons, such as hormones and genes that get disrupted when brain regions are developing in the male and female fetus, she said.

These biological changes during fetal development lay the groundwork that creates a vulnerability to mood disorders, such as depression, she said.

In addition, women tend to be more tuned into their emotions, and better able to describe them when depressed, Goldstein said. Men might not recognize their symptoms as depression, perhaps denying or hiding their unhappiness, so the illness might get overlooked in men until it becomes more severe.

Here are seven ways that depression may look different in men and women.

Women are more likely to ruminate when feeling depressed.

Dwelling on and rehashing negative feelings, known as ruminating, occurs more commonly in women who have depression in comparison to men who have the illness. This behavior may involve negative self-talk, crying for no obvious reason and blaming oneself.

Rumination does not help people, and in fact tends to make them feel worse, Goldstein said. Unlike women, men tend to distract themselves when feeling down, which helps ease depression. [5 Controversial Mental Health Treatments]

Men with depression are more likely to abuse alcohol and other substances.

Men may drink heavily or turn to illegal drugs to medicate themselves prior to the onset of depression, and this is particularly true of teenage boys, Goldstein said. In women, substance abuse tends to occur after the onset of depression, or as anxiety levels increase, she said.

Depressed men may also try to mask their sadness by turning to other outlets, such as TV, sports and working excessively, or engaging in risky behaviors, such as gambling, smoking, unsafe sex or driving recklessly. Depression is also more likely to show up as anger and irritability in men and teenage boys, Goldstein said.

Women may respond differently to stressful life events.

Women may be more likely to become depressed in response to a stressful event. Some evidence suggests that when women experience stressful situations, such as a death in the family, a difficult relationship or losing a job, they tend to respond in a way that prolongs their feelings of stress more so than men do.

This may be because of interactions among stress hormones, female reproductive hormones and mood-regulating neurotransmitters, Goldstein said.

Men's symptoms of depression may be harder for others to recognize.

Although women are hit harder by depression and are more vulnerable to it because of their biology, the illness is missed more frequently in men, Goldstein told Live Science.

Health care professionals and even family members may not pick up on depressive symptoms in men, so they can end up with severe depression before it's detected, she explained.

Women are more likely than men to have depression and a co-existing eating disorder.

Depression and eating disorders, such as anorexia and bulimia, often go hand in hand. Depression is also much more likely to occur at the same time as an anxiety disorder in women, such as panic disorder or obsessive-compulsive behavior.

Men and women might respond differently to antidepressants.

Women may be more likely to become depressed in response to a stressful event. Some evidence suggests that when women experience stressful situations, such as a death in the family, a difficult relationship or losing a job, they tend to respond in a way that prolongs their feelings of stress more so than men do.

This may be because of interactions among stress hormones, female reproductive hormones and mood-regulating neurotransmitters, Goldstein said.

Men are more likely to commit suicide.

Because depression symptoms in men can go longer without being diagnosed or treated, the condition might develop into a more devastating mental health problem. Men suffering from depression are also more likely to be successful than women when they attempt suicide.

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The remains of women and a child have been discovered at a burial mound at Cahokia, considered North America's first city, which previously was thought to hold only men, researchers say.

A closer look at a grave at Cahokia, located in Illinois near St. Louis, Missouri, has revealed that a blanket of beads is intertwined around a man and a woman of high status.

"In re-examining the beaded burial, we discovered that the central burial included females," study co-author Kristin Hedman, a physical anthropologist with the Illinois State Archaeological Survey (ISAS), said in a statement. "This was unexpected." [Cahokia to Area 51: The 10 Strangest Places on Earth]

Archaeologist Melvin Fowler, who died in 2008, discovered the enormous burial ground in 1967 during the excavation of an unusual mound with a ridgetop. The site, now called Mound 72, contained five mass graves, each holding 20 to more than 50 bodies. There were dozens of other bodies buried by themselves or in groups at the site, bringing the total count to 270, Fowler found.

Scientists dated the burials to between A.D. 1000 and A.D. 1200, during the rise and peak of Cahokia's power and influence, the researchers said. Some of the bodies were placed on cedar piles, indicating that they were high-status individuals, according to the researchers.

"Mound 72 burials are some of the most significant burials ever excavated in North America from this time period," said study co-author and ISAS Director Thomas Emerson.

Grave problems

Several analyses of the burials haven't held up, however. Mound 72 holds two central bodies that are placed top of each other. These bodies are separated and surrounded by a blanket of beads, and several other bodies from the same time period surround them.

Fowler and other archaeologists thought that these bodies were two high-status men who were surrounded by servants. Moreover, the beads look like a beaded cape or blanket that was originally shaped like a bird, they said.

The bird motif is usually related to warriors and supernatural beings in Native American cultures, so Fowler suggested that the two central males represented mythical warrior chiefs, the researchers said.

Once this interpretation was made public, many experts viewed Cahokia as "a male-dominated hierarchy," Emerson said.

A fresh look

When Emerson and his colleagues re-examined the evidence — including the archaeologists' maps, notes and reports — they came to a conclusion different from Fowler's. For instance, the early archaeologists said there were only six bodies associated with the beaded burial, but the new team found 12.

Moreover, a skeletal analysis revealed that the high-status pair weren't two men, but a man and a woman. The bodies near the power couple are also male-female pairs, and one individual was a child, the researchers said.

"The fact that these high-status burials included women changes the meaning of the beaded burial feature," Emerson said. "Now, we realize we don't have a system in which males are these dominant figures and females are playing bit parts. And so, what we have at Cahokia is very much a nobility. It's not a male nobility. It's males and females, and their relationships are very important." [The 7 Most Mysterious Archaeological Finds on Earth]

The new discoveries are consistent with other Cahokia findings, Emerson said.

"For me, having dug temples at Cahokia and analyzed a lot of that material, the symbolism is all about life renewal, fertility, agriculture," he said. "Most of the stone figurines found there are female. The symbols showing up on the pots have to do with water and the underworld. And so now, Mound 72 fits into a more consistent story with what we know about the rest of the symbolism and religion at Cahokia."

Not a warrior culture

It's unlikely that the beaded blanket symbolizes some type of warrior message, Emerson said. Instead, an analysis of the burial mound suggests that the Cahokia honored both men and women, he said.

"When the Spanish and the French came into the Southeast as early as the 1500s, they identified these kinds of societies in which both males and females have rank," he said. "Really, the division here is not gender; it's class."

"People who saw the warrior symbolism in the beaded burial were actually looking at societies hundreds of years later in the Southeast, where warrior symbolism dominated, and projecting it back to Cahokia and saying: 'Well, that's what this must be,'" Emerson said. "And we're saying, 'No, it's not.'"

The study was published in the July issue of the journal American Antiquity.

Original article on Live Science.

Science fiction promises that the world can be dramatically different — and presumably better — from what we experience every day, if we can only imagine it. We can have jetpacks, oscillation overthrusters, lightsabers and transporters. We can pilot starships, trade jibes with talking raccoons or sarcastic robots, and hitchhike across the galaxy carrying only a towel.

But science fiction is also grounded in reality, shaped by creators who can harbor prejudices that infect their imagined worlds. [Science Fact or Fantasy? The Reality of 20 Imaginary Worlds]

Scientists recently investigated how gender prejudices might surface in sci-fi by looking at a complex fictional universe that unfolded over half a century — the British television program "Doctor Who."

The long game

Since it first aired in 1963, the show about a regenerating Time Lord traveling through space and time has featured a number of male and female supporting characters who happened to be scientists. For the study, researchers evaluated whether they saw gender-related differences in the representations of 222 scientist characters — 56 women and 166 men — who appeared on the series from 1963 to 2013, but who were not regular members of the show's cast.

Earlier research in this area typically judged female representations of scientists in films and television simply by counting heads, or by looking only at female characters and how they behaved or how they were treated, study co-author Lindy Orthia, an associate director of science education at the Australian National University (ANU), told Live Science in an email.

But this time, Orthia and her co-author Rachel Morgain, also at ANU, compared and analyzed both male and female scientist characters in one television series, to gauge whether or not they were represented as equally competent scientists.

To judge competency, Orthia and Morgain looked at each character's title, whether or not they performed any science on-screen, and how autonomous they were in the scientific workplace.

They also noted if a character's role was important to the episode's plot, and whether their scientific discipline was in health or medicine, fields that traditionally have held fairly equal numbers of women and men in Britain.

The invisible enemy

Across the entire study and within each decade, male scientists outnumbered women, the researchers found. However, the ratio of female to male scientists rose from decade to decade, climbing from 15 percent in the 1960s to 28 percent in the 1980s. By the 2000s, 42 percent of the scientist characters in "Doctor Who" were women.

And when it came to scientific competency, the parallels between men and women were much closer.

Male scientists were somewhat more likely to be autonomous, or to hold positions of authority — 83 percent, compared to 71 percent of the women. But otherwise, there were "no significant differences" between men and women, the authors wrote in the study. Science honorifics were used for 25 percent of the women and for 30 percent of the men. And 75 percent of both male and female scientists performed science on-screen.

"Our research suggests 'Doctor Who' treated women and men more or less equally — aside from casting women as scientists less often," Orthia said.

In fact, of the nine female scientist characters who appeared in episodes from the 1960s, 100 percent of them performed science on-screen, hinting that "Doctor Who" creators were making a deliberate effort to be inclusive, the authors wrote in the study.

And in the 1968 episode "The Web of Fear," when a soldier condescendingly questioned scientist Anne Travers, asking her, "What's a girl like you doing in a job like this?" her answer was refreshingly matter-of-fact: "Well, when I was a little girl I thought I’d like to be a scientist. So I became a scientist," she said.

"From as early as the 1960s there was some very right-on dialogue about women in science in the show," Orthia told Live Science. "We think that, on average, the creators are keen to promote gender equality in science." [Countries with the Most and Least Gender Equality]

Human nature

However, the researchers also found evidence of "Doctor Who" linking a character's scientific competency to gender stereotypes.

In examples of 13 scientists who were clearly failures, many of the men are described by the authors as "effeminate," and "gender nonconforming."

A didactic and patronizing scientist character named Hobbes in the 2008 episode "Midnight" is soft and "flabby", the authors wrote, and comes across as "impotent" both in his lack of sexual interest in his female assistant, and his inability to act decisively during a crisis.

Consequently, Hobbes proved to be inept at detecting the threat in a dangerous alien encounter, placing a number of people — including the Doctor — in jeopardy.

Other incompetent scientists answered to leaders who suppressed men or rejected behaviors associated with men. The 1969 serial "The Dominators" introduced an alien race known as Dulcians, who rejected warfare of any kind, and appeared weak and ineffectual next to their rivals. Dulcian male scientists were clean-shaven and wore low-cut dresses, and their investigation of vanished radiation in an irradiated site was almost comically incompetent.

And some of the women scientists who failed at science were "domineering" and "man-belittling," such as the Hilda Winters character in the 1974–1975 serial, "Robot," whom the authors labeled, "the unpleasant face of feminism" for her confrontational, mocking demeanor.   

Overall, the researchers found that "Doctor Who" did portray women scientists in a positive light, though its track record was far from perfect.

"The statistically equal treatment of female and male scientist characters is encouraging, but is not an excuse for complacency," Orthia said.

"There are quite a lot of successful, credible female scientist characters in the show, but they and their credible male counterparts seem to be characterized as fitting in with an individualist, rugged culture of science," she added.

"Culturally, it still perpetuates science as a masculine pursuit."

The findings were published online in the August edition of the journal Sex Roles.

Original article on Live Science.

Contrary to what people might think, the money aspects of a marriage — the current earnings of a couple, or a wife's ability to support herself in the event her marriage breaks up, for example — don't appear to play a role in divorce, a new study suggests.

Rather, for couples who wed between 1975 and 2011, whether husbands were doing full-time work outside the home was linked with the couples' divorce risk, the study showed. But for couples who wed before that, the share of the housework done by the wife affected the risk of divorce. In other words, a couple's paid and unpaid work can affect the stability of a marriage.  

"It isn't the money that predicts the risk of divorce — the cash stuff doesn't matter," said study author Alexandra Killewald, a professor of sociology at Harvard University. It's the behaviors of husbands and wives in a marriage — employment status and the division of housework — that may have symbolic value to each other about whether men or women are meeting the (potentially gendered) expectations of spouses, such as the husband-breadwinner and wife-homemaker roles, that affect a couple's divorce risk, she suggested. [6 Scientific Tips for a Successful Marriage]

Marriage is a social institution, and couples have expectations of what each partner will do once they enter into it, Killewald said. As these expectations have changed over time, so have the factors that may affect a couple's risk of divorce, according to the study, published July 28 in the journal the American Sociological Review.

Divorce predictors

In the study, Killewald analyzed data collected from the Panel Study of Income Dynamics, an ongoing survey of American families conducted by scientists at the University of Michigan, which researchers often use to study divorce. Killewald used data collected in the U.S. between 1968 and 2013 from more than 6,300 different-sex couples involved in a first marriage, in which the age of both spouses was between 18 and 55.

Killewald also developed computer models to predict the risk of divorce based on financial reasons, such as the share of housework done by husbands and wives, family income, full- or part-time employment by each spouse, and a wife's economic independence if her marriage broke up. In addition, she took into consideration other variables that may affect the stability of a marriage, such as the spouses' age, education, race and religion, as well as whether couples owned a home or had children.

The researcher did not look at how often a couple argued over spending habits or disagreed about financial priorities, she noted.

To understand how the roles and responsibilities in marriage changed over time and influenced the chance of divorce, Killewald compared couples married in 1974 or earlier with those married in 1975 or later. [The Science of Breakups: 7 Facts About Splitsville]

The findings showed that in couples married before 1974 —who might have more traditional views on the division of labor between spouses in the workforce and at home than couples married more recently — the share of housework done by the wife was tied to the risk of divorce. For example, in these couples, wives who did 75 percent of the housework were less likely to divorce than wives who did 50 percent of the housework, according to the findings.

This result shows that couples' expectations for their marriages may conform to a society's expectations for what it means to be "a good wife," Killewald said. But even in more recently married couples, the study found that women were still doing the majority of housework, although men were expected to pitch in more and typically did.

However, husbands in the more-recently married couples who did not have full-time employment faced a higher risk of divorce than husbands who worked full time, according to the findings.

In marriages since 1975 in which husbands did not have a full-time job for reasons that were not a deliberate choice, such as job loss or only finding part-time work, the average risk for divorce in the next year was 3.3 percent, compared with 2.5 percent in the next year in husbands who were employed full time.

These findings suggest that the male breadwinner role remains a key feature of many marriages, Killewald told Live Science. 

Taken together, the findings suggest that although women in contemporary marriages may have more role flexibility when deciding whether to seek full-time work outside the home or focus on household work, without it affecting the stability of their marriage, this is not the case for men. And this speaks to the idea that society may not have changed much in  its expectations of a husband's role and responsibilities in a marriage, Killewald said.

The findings also suggest that for most of today's couples, a woman's role in the labor force and at home may have less influence on whether spouses split up. In other words, women's rise in the labor market does not appear to undermine a marriage, Killewald said.

Originally published on Live Science.

People who identify as transgender should not be considered to have a mental health disorder, according to a new study from Mexico.

The World Health Organization currently lists transgender identity as a mental health disorder, and the new study is the first in a series of research aimed at finding out whether this categorization is apt. The study will be repeated in Brazil, France, India, Lebanon and South Africa, according to the researchers.

In the new study, published today (July 26) in the journal The Lancet Psychiatry, the researchers investigated whether the distress and dysfunction associated with transgender identity were the result of social rejection and stigmatization or an inherent part of being transgender. [5 Controversial Mental Health Treatments]

Experiencing "distress and dysfunction" is often considered a defining feature of having a mental health disorder, according to the study. But other factors can cause these feelings as well, including experiencing rejection or stigmatization.

The researchers interviewed 250 transgender people in Mexico City. The people in the study reported at what age they first became aware of having a transgender identity, as well as their experiences of psychological distress, social rejection, difficulty functioning in their daily life, and violence, according to the study.

The researchers found that 76 percent of the participants reported experiencing social rejection, and 63 percent reported being the victim of violence as a result of their gender identity. In many cases, social rejection and violence against transgender individuals occurred within families. (The frequency with which such acts occurred within participants' own families was "particularly disturbing," the researchers wrote.)

Using a statistical analysis, the researchers found that social rejection and violence were strong indicators that a transgender person would experience distress and dysfunction. Having a transgender identity, on the other hand, was not a predictor of stress or dysfunction, they found.

"Our findings support the idea that distress and dysfunction may be the result of stigmatization and maltreatment, rather than integral aspects of transgender identity,” Rebeca Robles, a researcher at the Mexican National Institute of Psychiatry and the lead author of the study, said in a statement. In other words, the distress and dysfunction that the transgender individuals reported in the study was more likely the result of being treated with prejudice, rather than inherent to having a transgender identity in and of itself.

"This study highlights the need for policies and programs to reduce stigmatization and victimization of" people with transgender identities, Robles said. The removal of transgender diagnoses from the classification of mental disorders can be a useful part of those efforts," she said.

Originally published on Live Science.

Men who work long hours make their wives feel more stressed and rushed, but women who work long hours don't have the same effect on their husbands, new research on Australian families suggests.

"The job demands of men affect women, but we didn't find any evidence that the opposite was the case," said study co-author Lyn Craig, a sociologist at the University of New South Wales in Australia. "I think it's because women have the responsibility to make the family work around the male job." [6 Scientific Tips for a Successful Marriage]

Couple dynamics

Though men have dramatically increased the time they spend at home and with the family sincethe 1960s there's still no contest: Women, on average, spend nearly 5 more hours a week on household chores than men do and spend double the amount of time tending to young childrens' physical needs, according to the 2015 American Time Use Survey.

But it's difficult to tease out the possible effects of these dynamics using typical data. Some studies show that women feel more pressed for time, for instance, but those studies typically study individuals, without comparing two halves of a couple and seeing how one person's choices affect the other's.

To get a better understanding of those couple dynamics, Craig and her colleagues looked at the 2006 Australian Time Use Survey, which included 756 Australian couples with children at home. About a quarter of these households had just a man as the sole breadwinner, about a quarter had two full-time working parents, and a little less than half had a wife who worked part time and a husband who worked full time. Nearly four in 10 of the fathers worked more than 50 hours a week.

The survey asked people to record 5-minute time diaries over one or two days, describing their activities and answering how often they felt rushed or pressed for time.

Contaminated time

The families were frazzled, the researchers found. Nearly 70 percent of women and 62 percent of men felt rushed for time "always" or "often," the researchers reported online June 21 in the Journal of Marriage and Family.

Women reported having two fewer hours a week of "uncontaminated" leisure, or time for purely fun pursuits. An example of pure or "uncontaminated" leisure would be curling up to read a book alone or seeing friends sans husband and kids, whilecontaminated leisure would include hanging out with friends on a playdate or going to a baseball game with the family, Craig said.

When men worked long hours (more than 50 hours a week), their wives reported feeling more rushed and spent more time multitasking on household duties. This was the case no matter whether the woman was not employed outside the home, employed full time or employed part time, the researchers said.

However, when women worked longer hours, they spent more time multitasking with household chores and cut back their uncontaminated free time.

What's more, men who work on the weekends still manage to preserve their pure leisure, while women who work evenings and weekends have less uncontaminated leisure time. [13 Facts on the History of Marriage]

Interestingly, men didn't seem to mind their contaminated leisure as much as women did.

"While pure leisure is relaxing for both men and women, contaminated leisure is relaxing for men but not women," Craig said. She speculated that this may have to do with family dynamics during family activities. "If you're both present and both have the kids there, it feels more like work for women than men," she said.

Societal changes

The findings offer statistical data affirming what many harried families have experienced firsthand, said Stephanie Coontz, author of "Marriage, a History: How Love Conquered Marriage" (Penguin Books, 2006).

When men work long hours, that stress rubs off on their spouses, Coontz said.

And if men are working long hours, that means they aren't there for chores that must be done at certain times, such as cooking dinner or giving kids a bath, Coontz told Live Science. That means women are left with the brunt of these so-called "low-control" tasks, she said.

But the main issue is that full-time workers have longer hours than in generations past, Craig said. And that may be bad news for familial well-being.

"As workplaces are becoming more demanding in recent years and couples are spending more time in the workforce, it's having wash-out effects on the household which are probably not that good in the long run," Craig said.

Coontz agreed. While some of these patterns can be hashed out within the family, for the most part the problem sholdn't "be solved at an individual level," Coontz said.

Instead, the underlying problem is that workers now are facing longer hours than ever, with scant paid paternity leave or maternity leave, sick leave or vacation, she added.

"It shouldn't have to be that women and men fight over how to equally share three full-time jobs," Coontz said.

Original article on Live Science.

What is "Frozen" doing to kids' psyches?

New research finds that preschoolers who watch Disney's princess movies are not only more likely to don the sparkling ultrafeminine fashion but also to internalize stereotypical gender roles.

Researchers surveyed almost 200 4-year-old girls and boys, as well as the children's mothers and teachers, to learn about each kid's Disney movie- and TV-watching habits, favorite princesses and playtime routines. Participants were surveyed again a year later. [10 Scientific Tips For Raising Happy Kids]

"Girls who were into the princess culture at the first wave were more gender-stereotyped one year later," said study lead researcher Sarah Coyne, an associate professor of family life at Brigham Young University in Utah. "The princess culture is really kind of contributing to this girly girl world that we're seeing in preschool and even beyond." 

The results held even after the researchers accounted for how "girly" participants were at the study's start, suggesting that high engagement with Disney princess films and shows led girls to act in more gender-stereotyped ways, such as playing with more feminine-stereotyped toys, including tea sets and fairy wings, as opposed to more gender neutral-toys, including paints and puzzles.

The findings suggest that girls are learning that the princesses' feminine qualities, such as their looks, are valued more than other qualities, such as their brains, Coyne said.

Coyne doesn't recommend that parents do away with princess activities, such as movies,, but she encourages them to mention other areas in which princesses excel. "There's nothing inherently wrong with telling a girl that she's beautiful," Coyne said. "But they need to hear more that they're smart and hardworking. Because when we value appearance over everything else, starting from age 3, it sends a very strong message about what's valued in girlhood and womanhood."

Princess culture

Coyne, who studies gender and media, got the idea for the study after hearing journalist Peggy Orenstein, author of "Cinderella Ate my Daughter" (Harper 2011), speak at a conference. [The Destructive Culture of Pink Princesses: Q&A with Peggy Orenstein]

That, added with the knowledge that TV shows and movies can develop and reinforce children's attitudes about gender stereotypes (according to a 1996 meta-analysis of 30 studies in the journal Annals of the International Communication Association), spurred Coyne to start the study.

"My daughter Hannah was 3 at the time, and full-on into princesses," Coyne told Live Science. "I thought, 'I study media, how have I not thought about this ever?'"

Girls vs. boys

High princess engagement had different effects on boys than it did on girls, the researchers found.

None of the boys were as invested in the princesses as the girls were, Coyne said. But, the findings were "actually quite positive for boys," Coyne said. While a lot of the preschool boys acted, for lack of a better term, like boys, those who engaged more with Disney's princess products tended to act a little androgynous, or show characteristics of both boys and girls.

For instance, the boys with more "princess time" were nicer to their friends and had a better body image, especially when they talked with their parents about the TV shows and movies they were watching, Coyne said. The fact that princes look more androgynous in some of Disney's more recent movies may help preschool boys, who are often exposed to hypermasculine body images, realize that other body types are acceptable, the researchers said.

Surprisingly, little girls who actively engaged with princesses at age 4 showed stereotypical female gender beliefs at age 5 only if their parents reported talking to the girls about the media. The researchers aren't sure what the parents talked about, but Coyne has some ideas.

Most parents view Disney movies as "safe" and "a great thing," she said. Parents might speak about the princesses in supportive terms, calling them beautiful, as opposed to having the child think critically about the show.

Instead, parents could talk about how the princesses are smart, or how they try to help their families, such as in "Mulan," or "Frozen." Coyne began doing this with her daughter, and says she saw a shift almost right away.

"She's this independent little tomboy — she's 8 now, and likes Hermione from Harry Potter," Coyne said. "She still tolerates the princess culture, but I've seen her grow into such a confident little girl. I think that's, in part, because of the way that I have chosen to speak to her about the princess culture and girlhood in general."

Limitations of gender stereotypes

Still, there's nothing wrong with being feminine. "So many feminine traits are great — being nurturing, kind, loving and sharing," Coyne said. But research has found that girls who limit themselves to gender stereotypes tend to limit themselves throughout life, she said.

These girls may think they're not as good at math and science, and think there are fewer career options for themselves later in life, Coyne said the research shows. They're also more likely to place a greater importance on appearance, and less likely to go exploring if they think they're going to get dirty, she said.

"It's problematic when girls limit themselves because of a culturally defined belief," Coyne said.

She added that the study has limitations. The 198 children followed in the research are from mostly white, middle-class families, and may not fully represent other children across the country, the researchers said.

The study was published online June 18 in the journal Child Development.

Original article on Live Science.

The conscious mind is quick to adapt to information that flies in the face of stereotype, but the subconscious may ignore even the most glaring of facts, new research finds.

When people are given two names, Jonathan and Elizabeth, and asked who is a doctor and who is a nurse, the respondents typically say that each is equally likely to be in either profession. But experiments based on how quickly people link the names with the jobs reveal that people's brains run on stereotype: The individuals are much more likely to associate Jonathan, a man, with doctoring, and Elizabeth, a woman, with nursing.

This kind of implicit association, or subconscious pairing based on stereotype, is well-known in psychology. But now, researchers find that even after people are directly told that Jonathan is a nurse and Elizabeth is a doctor, these implicit biases don't change. The stereotype acts like a "mental firewall" that seems to prevent people from updating their subconscious attitudes with the facts, said Jack Cao, a graduate student in psychology at Harvard University in Massachusetts. [6 Myths About Girls and Science]

Explicit vs. implicit

Cao and his advisor, Mahzarin Banaji, a social psychologist at Harvard, built their study on a body of research that finds that people's conscious attitudes tend to be more enlightened than their subconscious processing. These subtle, snap-judgment attitudes reveal themselves through implicit-association tasks, in which people are shown two words — say, "Elizabeth" and "doctor" — and asked to press a button if the words are related. Concepts that are linked more closely are processed more quickly, such that people tend to press the button faster if "doctor" is paired with Jonathan instead of with Elizabeth.

The researchers had their study participants complete one of these implicit-association tasks, and also asked the individuals to report their conscious beliefs about Jonathan's and Elizabeth's professions. The investigators then told the participants directly either that Jonathan was a doctor and Elizabeth a nurse, or that Elizabeth was a doctor and Jonathan a nurse.

Unsurprisingly, the participants had no problem repeating these facts back to the researchers. But the implicit-association task revealed that no matter what the participants had been told, they still subconsciously saw Jonathan as a doctor and Elizabeth as a nurse. 

"When we look at people's implicit responses, they don't update quite as quickly or easily or accurately" as explicit beliefs, Cao told Live Science.

Sticky beliefs

The researchers repeated their experiments with nearly 3,400 participants. In addition, the scientists varied the circumstances slightly: In one study, they used the names Richard and Jennifer and the professions doctor and artist. In another, the researchers picked made-up names that people wouldn't be able to associate with anyone they knew: Lapper for the man and Affina for the woman. In both cases, the researchers found the same results. People who were told that the man was in the female-stereotyped profession and the woman in the male-stereotyped profession had no trouble accepting those facts consciously, but still made implicit judgments based on stereotype.

In a final study, the researchers used two male names, Matthew and Benjamin, and the professions scientist and artist. These results showed that, without stereotype to rely on, people did update their subconscious beliefs easily; their implicit associations matched their explicit beliefs.

"There seems to be some stickiness in our implicit beliefs," Cao said. In their paper, published today in the journal Proceedings of the National Academy of Sciences (PNAS), Cao and Banaji likened the phenomenon to the old riddle about a father and son who are in a terrible car accident. The father dies, and the son is rushed to the hospital, where the surgeon takes one look and says, "I can't operate on this patient! He's my son."

"In 1985, one of the authors of the present paper attempted to solve this riddle by weakly offering that perhaps the surgeon was the biological father and the other man was the adoptive father," the researchers wrote. "Much to this author's chagrin, the correct answer is that the surgeon is the boy's mother."

These stereotypes could be important in real life. In one study, published in PNAS in 2014, another team of researchers found that the stronger people's implicit association between men and math, the less likely the people were to hire a woman for a hypothetical job involving basic arithmetic. [5 Reasons Women Trail Men in Science]

Some studies have found that there are ways to budge people's implicit attitudes, Cao said. For instance, if people have a neutral attitude toward a man, it's easy to transform that into a strong negative reaction if you tell people that the man is a child molester. But fighting ingrained stereotypes may be a more difficult task, Cao said.

"There's a part of you that's clinging to the stereotype, even though you know the stereotype doesn't apply," Cao said.

Original article on Live Science.

When it comes to your wages, do looks matter? A new study says yes.

However, in one aspect of appearance — being well groomed — there was a gender gap, according to the study.

The researchers found that overall, men and women who were considered more attractive earned more money than their less-attractive counterparts, according to the study, published online last month in the journal Research in Social Stratification and Mobility. But when grooming was factored in for men, the numbers evened out. For women, those who were well-groomed women actually had higher incomes than poorly groomed women, regardless of their "natural" level of attractiveness, the researchers found. [10 Things You Didn't Know About You]

"For both men and women, grooming matters more than attractiveness: Being attractive is not enough; it is doing attractiveness appropriately [being well groomed] that proves one's deservingness and is what gets rewarded in the labor market," the authors of the study, Jaclyn Wong, a Ph.D. student in sociology at the University of Chicago, and Andrew Penner, an associate professor of sociology at the University of California, Irvine, wrote in their paper.

In the study, Wong and Penner analyzed data that were previously gathered on 14,600 adults during the the National Longitudinal Study of Adolescent to Adult Health, which tracked a nationally representative sample of people from adolescence to adulthood. The participants were in grades 7 to 12 when the study began, in 1994, and were ages 24 to 32 when researchers last followed up with them in 2008.

At several points during the study, the participants sat down for in-depth interviews, and at the end of each interview, the interviewers rated the attractiveness of the participants as unattractive, average, attractive or very attractive. In addition, the interviewers rated how well groomed they thought the participants were on a similar four-point scale: poorly groomed, average grooming, well groomed or very well groomed. 

As adults, the participants provided information about their yearly incomes, according to the study. (The men reported a yearly income that was, on average, $7,000 greater than that of the women.)

The researchers found that overall, attractive people earned about 20 percent more money than "average" people.

In addition, when the researchers compared people of the same level of attractiveness to one another, they found that well-groomed people earned more money than poorly groomed people.

One possible explanation for this effect is that putting effort into one's appearance signals that a person will put effort into other activities, such as his or her job, the researchers said.

The researchers also found that once grooming was taken into consideration, women who were well groomed but unattractive actually earned more money than well-groomed attractive women. This effect was not observed in men.

The findings show that grooming — which requires paying attention to social cues, spending money and conforming to certain social identities — "is the key that provides women with the [benefits] associated with attractiveness," the researchers said.

A previous study found that spending more time on grooming was linked with higher wages for men in minority groups. That study also suggested that for women, spending more than 90 minutes a day on grooming had a negative effect on wages. Excess grooming could signal that people are focused more on their appearance than on their job, the researchers speculated.

Follow Sara G. Miller on Twitter @saragmiller. Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science.

In North Carolina and other states, a new culture war has erupted. This time, the battlefield is bathrooms.

In March, North Carolina enacted a law (colloquially known as HB2) that requires that people use only bathrooms that correspond to the gender on their birth certificates. The law affects transgender individuals, who identify as a gender other than the one they were assigned at birth. Other states have considered similar bills, to great controversy.

To some people, public bathrooms may seem like unassuming spaces — necessary but not worth too much thought. But these bathroom bills illustrate that public restrooms are the stage for many complex social interactions, and that the availability of a place to relieve oneself is crucial in society.

Public or private?

Gender-segregated public restrooms are either very old or very new, depending on how you look at the question. They arose in the Victorian era, along with widespread plumbing, meaning they've been around almost as long as the modern bathroom itself. On the other hand, having privacy for peeing is a relatively modern phenomenon.  

The notion of privacy itself is shifting constantly, and it can be hard to determine how people of the past viewed the importance of privacy in their bathroom habits. Ancient Rome, for example, is famous for its multiseater bathrooms, where people sat side by side on benches, without partitions, to do their business. However, there are hints that a concept of privacy might have existed. In Hadrian's Villa, a second-century site in Tivoli, Italy, there were multiseat facilities for servants and staff, according to a 2003 paper in the Journal of Roman Archaeology. However, the emperor and high-status guests seem to have had access to relatively private single-seaters. [Through the Years: A Gallery of the World's Toilets]

"[T]he provision of single-seaters, especially for guests, shows that, when space and money were no object, [the elite] preferred single toilets," wrote study researcher and independent archaeologist Gemma Jansen.

The first gender-segregated public restroom on record was a temporary setup at a Parisian ball in 1739, said Sheila Cavanagh, a sociologist at York University in Canada and author of "Queering Bathrooms: Gender, Sexuality, and the Hygienic Imagination" (University of Toronto Press, 2010). The ball's organizers put a chamber box (essentially a chamber pot in a box with a seat) for men in one room and for women in another.

"Everyone at the ball thought this was sort of a novelty — something sort of eccentric and fun," Cavanagh said.

But for the most part, public facilities in Western nations were male-only until the Victorian era, which meant women had to improvise. If they had to be out and about longer than they could hold their bladders, women in the Victorian era would urinate over a gutter (long Victorian skirts allowed for some privacy). Some would even carry a small personal device called a urinette that they could use discretely under their skirts and then pour out, Cavanagh said. Strangely, these urinettes were sometimes shaped like the male genitals. [How Much Urine Can a Healthy Bladder Hold?]

This lack of female facilities reflected a notable attitude about women: that they should stay home. This "urinary leash" remains a problem in some developing nations, said Harvey Molotch, a sociologist at New York University and co-editor of "Toilet: The Public Restroom and the Politics of Sharing" (New York University Press, 2010). Women in India today, for example, often have to avoid eating or drinking too much if they have to be out in public, because there is no place for them to go, Molotch told Live Science.

Ladies and gentlemen

Thus, the first gender-segregated restrooms were a major step forward for women. Massachusetts passed a law in 1887 requiring workplaces that employed women to have restrooms for them, according to an article in the Rutgers University Law Review. By the 1920s, such laws were the norm.

Victorian-era Americans were segregated by gender in many spaces, Molotch said. There were ladies-only waiting rooms in train stations, and female-only reading rooms in libraries. As sex segregation has fallen to the wayside in other public spaces, bathrooms remain the last holdout, he said.

"Restrooms are a very funny place, because they're where the most intimate actions occur that are also in public," Molotch said. In the U.S., bathrooms are partitioned with flimsy barriers with lots of gaps, in part because of anxiety over what might go on in a fully private stall. Sex and drugs are the most common of these concerns, he said.

Meanwhile, people observe rigid social rituals to keep up the illusion of privacy. Men, for example, can't be seen looking at the genitals of other men, Molotch said, but also can't be perceived as trying not to look. [10 Things That Make Humans Special]

"The disgust attached to excretion makes people bothered by the sounds and smells of others, and the shame of this private action makes many people concerned about being witnessed in the act, even indirectly," said Nicholas Haslam, a psychology professor at the University of Melbourne and author of "Psychology in the Bathroom" (Palgrave Macmillan, 2012). Excretion is seen as unfeminine, Haslam told Live Science, so women are under particular pressure to hide their bathroom activities, especially from men.

"Finally, the act of going to the bathroom makes many people feel vulnerable, exposed, and unsafe," Haslam said.

Bathroom bills like North Carolina's often reflect ideas about sex and safety, Cavanagh said. However, there are no documented instances of a transgender person attacking anyone in a public bathroom, she said. A survey published in the Journal of Public Management and Social Policy in 2013 did find, however, that 70 percent of the transgender respondents from the Washington, D.C., area had experienced harassment or assault in bathrooms, or had been denied access to facilities.

Ultimately, fears over allowing bathrooms to be used by people of different birth sexes may have more to do with the symbolic nature of public restrooms than with practical concerns. Transgender people challenge the notion that a person's gender and their biological sex at birth are one and the same in all cases, Molotch said, which makes some people uncomfortable. However, he suspects that the backlash will simmer down and that gender-segregated toilets will persist, with an agreement that everyone will mind their own business.

"We all know there is nothing more important to transgender people than to 'pass,'" Molotch said, meaning that transgender people want others who casually encounter them to assume they are just like all of the other members of the gender they identify with. Most transgender people do not want others to wonder whether they are transgender, he said.

Follow Stephanie Pappas on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on Live Science.

The Pentagon announced last week that it would open up all positions in the military to women — including combat positions. But science, and history, suggest the road to combat equality may be a difficult one.

"As long as they qualify and meet the standards, women will now be able to contribute to our mission in ways they could not before. They'll be able to drive tanks, give orders, lead infantry soldiers into combat," U.S. Secretary of Defense Ashton Carter said at a news conference Thursday (Dec. 3).

The new decision isn't a surprise; the military had already lifted a ban on women in combat, noting that women in Iraq and Afghanistan were often on the front lines even when not formally assigned to combat positions. The Department of Defense had also previously required the armed forces to define gender-neutral standards for combat positions, which the Navy, Army, and U.S. Special Operations Command enacted. Over the past two years, each branch of the armed forces assessed the impact of opening combat positions to women and developed plans for how to integrate women into combat roles. Only the Marines recommended keeping certain combat positions closed to women. The new announcement means the Marines will open all their combat positions to women, and will make 220,000 positions across the military open to women.

What's still not clear, however, is exactly what physical standards will apply for each combat position. Whatever they are, it's unlikely there will ever be equal numbers of men and women in these combat positions, one expert said. A large reason for that is that men still have an edge when it comes to certain physical abilities. [Men vs. Women: Our Key Physical Differences Explained]

Similarities and differences

The old cliché is that women and men think so differently that it's as though they were from different planets. But when it comes to their brains, the difference is more akin to living in nearly identical houses in a generic suburb. A study published last week found that there's no such thing as a "male" or "female" brain, but rather that the brains of both sexes are a mosaic of malelike and femalelike features. Other studies have found that tiny, average differences between men and women in cognitive ability tend to wash out on the individual level.

But in one way, the sex difference is stark: Men are physically stronger than women, on average. A study in the Journal of Applied Physiology found that men had an average of 26 lbs. (12 kilograms) more skeletal muscle mass than women. Women also exhibited about 40 percent less upper-body strength and 33 percent less lower-body strength, on average, the study found.

The researchers found that height and weight differences between men and women could explain only about half of the difference in strength. Researchers reporting in 1993 in the European Journal of Applied Physiology found that men's brawn could also be attributed to a larger cross-section in individual muscle fibers. [5 Myths About Women's Bodies]

And a 2006 study in the same journal revealed that men had much stronger grips than women — the difference was so big that 90 percent of the women scored lower than 95 percent of the men. The team also looked at highly trained female athletes who excelled at sports requiring a strong grip, such as judo or handball. Though these women did have a stronger grip compared with other women, they still performed worse than 75 percent of the men on this task.

In general, men are also faster than women. The fastest woman in the world, Florence Griffith Joyner, ran the 100-meter dash in just 10.49 seconds in 1988, and that record remains unbroken. Yet her fastest time wouldn't have even qualified her for the men's 2016 Olympic competition, which requires competitors to finish the 100-meter sprint in 10.16 seconds or less.

However, women may have an edge in some physical tasks. Because women usually have more body fat and may be better at burning fat as energy early on in exertion, they could have better endurance than men, according to a 2001 study in the American Journal of Physiology, Endocrinology and Metabolism. Men have more muscle mass and greater levels of circulating testosterone, on average, which also means they use more energy than women do. And men's muscles tend to fatigue more easily than women's, possibly because women recruit muscle groups to share the load more efficiently, according to a 2003 study in the Journal of Applied Physiology.

Applications to real-life settings

Still, these numbers may only loosely translate to the battlefield. The push for the integration of women has forced the military to rethink the standards for combat positions.

For instance, in October, the Marine Corps instituted gender-neutral physical requirements, some of which were more rigorous than the previous requirements. For instance, all Marines will need to be able to scale a wall and evacuate a casualty, while other combat positions may require specialized tests, such as swimming 1.2 miles (2,000 m) with fins or scaling rickety ladders, according to the Marine Corp Times.

However, even with combat positions technically open to women, don't expect instant or even long-term parity between the sexes, said Agnes Gereben Schaefer, a senior political scientist with RAND Corp. in Pittsburgh, who published a study Dec. 3 on how to integrate women into the Marine Corps.

"We found that across foreign militaries, the number of women in these positions is very low," typically far below 10 percent, Schaefer told Live Science.

Schaefer and her colleagues found that even in the most wildly optimistic scenario, where 400 female candidates try out for Marine Corps infantry positions every year and 85 percent complete basic training, just 8 percent of the infantry would be female in 2030.

It's also not clear whether 85 percent of women could complete basic training. For instance, preliminary results from a recent Marine Corps study found that, of roughly two-dozen women who tried out for the "rifleman" position, only two could complete the training. Initial results from their study showed that male teams outperformed and had lower rates of injury than mixed units, according to the Marine Corps Times.

However, there could be ways to solve some of those problems. In some foreign militaries, women are allowed to train longer for some combat positions before being tested, Schaefer said.

"The big problem with physical injuries in women is that, when they're under load, they have a lot of stress fractures and things like that," Schaefer said. "If you allow them to train and condition their bodies over a longer period of time, then you have fewer of those injuries."

Leaders will also need to foster an environment that makes everyone feel "there's no favoritism either way," Schaefer said. "That reinforces the fact that the standards are the same, and if you can meet the standards, then you'll be treated equally."

Follow Tia Ghose on Twitterand Google+. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

Men still drink more than women in the United States, but the gap is closing, a new report finds.

Over the decade-long period between 2002 and 2012, the percentage of U.S. women who reported drinking in the past month increased, and so did the the average number of days that women reported drinking, according to the report from researchers at the National Institute of Alcohol Abuse and Alcoholism (NIAAA).

The percentage of women who reported drinking alcohol in the past 30 days increased from 45 percent to 48 percent over the study period. Among men, however, the percentage decreased slightly, from 57 percent to 56 percent, according to the findings published today (Nov. 23) in the journal Alcoholism: Clinical and Experimental Research. [7 Ways Alcohol Affects Your Health]

The average number of days that women reported drinking in the past month increased from 6.8 to 7.3 days, whereas in men, there was a slight decrease, from 9.9 to 9.5 days, the researchers discovered.

"We found that over [the study period], differences in measures such as current drinking, number of drinking days per month, reaching criteria for an alcohol use disorder and driving under the influence of alcohol all narrowed for females and males," Aaron White, the senior scientific advisor to the NIAAA director and lead author on the study, said in a statement.

"Males still consume more alcohol, but the differences between men and women are diminishing," White said.

The evidence of increasing alcohol use is particularly concerning given that women are at greater risk than men for a variety of alcohol-related health effects, including liver inflammation, heart disease, neurotoxicity and cancer, George Koob, the director of the NIAAA, said in a statement.

The researchers noted that the rates of alcohol use disorder and driving under the influence did not increase for women.

In fact, the percentage of women who met the criteria for an alcohol use disorder decreased slightly, and the percentage of men who met the criteria decreased significantly, from 10.7 percent to 9 percent, according to the report.

Similarly, the percentages of both women and men who reported driving under the influence of alcohol decreased over the study period, from 10.3 percent to 7.9 percent in women, and from 19 percent to 14.4 percent in men, according to the report.

The report also touched on binge drinking. Among 18- to 25-year-olds who were not in college, the percentage of women who reported binge drinking significantly increased, while the percentage of men who reported binge drinking significantly decreased. Binge drinking (defined as drinking five or more drinks on the same occasion) rates among 18- to 25-year olds who were in college did not change over the study period, according to the report.

Follow Sara G. Miller on Twitter @SaraGMiller. Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science.

A supposed treatment, called gay conversion therapy, that aims to change the same-sex attractions of gay people should not be offered to minors as it can cause serious psychological harm, according to a newly released federal agency report.

Advocates of such conversion therapy hold that people can change their sexual orientation. The counseling is typically offered to youngsters who identify as lesbian, gay, bisexual or transgender (LGBT).

But the new report, which was released by the Substance Abuse and Mental Health Services Administration, concludes that the technique is based on the faulty premise that there is something wrong with being gay or lesbian.

"Conversion therapy perpetuates outdated views of gender roles and identities as well as the negative stereotype that being a sexual or gender minority or identifying as LGBTQ is an abnormal aspect of human development," the authors of the report write. "Most importantly, it may put young people at risk of serious harm." [5 Things You Should Know About Gay Conversion Therapy]

Changing a fixed outcome

The term gay conversion therapy covers a wide range of practices, from talk therapy to electroconvulsive therapy to hormones that dampen libido. During the 1960s, for instance, gay men (who were often mandated by court to attend therapy) were forced to watch pornography while consuming nauseating substances. In recent years, psychologists have relied on talk therapy, often pinning the blame for being gay or transgender on dysfunctional family dynamics.

In 2012, the American Psychological Association conducted a review of 83 studies on gay conversion therapy conducted between 1960 and 2007. Though most were too poorly designed to draw conclusions, the few higher-quality studies found that people rarely switched sexual orientation, even after years of therapy, the report found.

The authors of the new report cited that review, finding that "no research has been published in the peer-reviewed literature that demonstrates the efficacy of conversion therapy efforts with gender-minority youth, nor any benefits of such interventions to children and their families."

In fact, several other research studies suggest that being gay is not a choice. Though the science behind being gay isn't fully developed, there are some hints that genetics or epigenetics — chemical tags on genes that alter their expression — may play a role in whether someone identifies as gay. Either way, orientation tends to be fixed in men by puberty. Though women tend to show greater "erotic plasticity" than men, even women who switch from identifying as gay to straight don't stop finding women attractive, according to a 2012 study in the journal Archives of Sexual Behavior. 

Fixing something that's 'fixed'

On a more fundamental level, the report authors also took issue with the notion that someone's identity or orientation needs to be changed in the first place. They said that same-gender sexual attractions are part of the normal spectrum of sexual orientation.  In general, psychological associations frown on mental health treatments focused on achieving a "fixed outcome," because these treatments can be harmful, the report authors wrote. [Top 10 Stigmatized Health Disorders]

The main problem with gay conversion therapy, however, is that it can fuel self-hatred, depression and anxiety, the report authors found. Many teens subjected to the practice have attempted suicide, while others have struggled for years with feelings of self-hatred or loss of sexual feeling.

The report authors also note that people who are gay, lesbian and transgender already face higher risks of suicidal thoughts and depression, as well as substance abuse problems, and an increased likelihood of experiencing victimization, violence and homelessness. However, those higher risks aren't inherent to being gay or transgender, but may instead arise due to hostility and discrimination from family, friends and society, the report authors found.

Instead of trying to "fix" someone's orientation or identity, mental health professionals should try to help teens explore their identity while also dealing with negative familial and societal reactions, the scientists said.

"Appropriate therapeutic approaches with sexual and gender-minority youth should include a comprehensive evaluation and focus on identity development and exploration that allows the child or adolescent the freedom of self-discovery within a context of acceptance and support," the report stated.

Follow Tia Ghose on Twitterand Google+. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

Although it’s often assumed that males who feel they are "manly" men are more likely to engage in violence than those who are less concerned about their masculinity, men who feel they don't meet perceived masculine gender norms and are stressed about it may be equally prone to violent acts, a new study finds.

Researchers found that men who feel they fall short of society's "macho man" standards and are unhappy about it may be more likely to commit violent assaults using weapons than men who are comfortable with their masculinity. 

In general, men are more likely than women to suffer from poor health and injury, likely because they tend to gravitate toward riskier behavior, the researchers said. Men typically are more prone than women to engage in substance abuse, binge drinking, reckless driving, violent acts and to carry weapons than women. [5 Myths About the Male Body]

The researchers tested their theory that men’s dangerous, risk-taking behavior stems from insecurity with their masculinity; when a man perceives himself to be less masculine than traditional societal standards and feels that others see him the same way, he is said to have “gender role discrepancy,” and the tension he feels is known as “discrepancy stress.”  

In 2012, the scientists conducted an online survey that probed how the male participants perceived masculinity standards and how their own self-image fit in with this perception. The 600 male participants, who were paid $2, were asked whether they felt as masculine as the average guy or if they wished to be more macho. The survey also included information about the individual's substance use and violent behavior.

The researchers found that the men with high discrepancy stress were more likely to be violent than the men who were not as concerned about their masculinity. The two groups, however, were not likely to differ significantly in their alcohol and drug use, the scientists said.

The researchers did not provide participants with a set standard for masculinity. In some cases, survey respondents interpreted "being macho" as being aggressive and hypersexual, while others saw it as being a good husband and father, said Dennis Reidy, the study’s lead author and a behavioral scientist at the Centers for Disease Control and Prevention.

The ages of the American survey participants ranged between 18 and 50 years, the researchers said, and the distribution of the respondents' ethnicities and incomes was consistent with the general population in the United States — 72 percent Caucasian, 13 percent Asian, 7 percent African-American and 7 percent Hispanic.

The participants had a median annual income of $37,000, although the most frequently reported income was $55,000, and salaries ranged from $5,000 a year to more than $100,000. The average age skewed slightly younger, at 27.2 years. The participants were also slightly more educated than the general American public, with the average participant having had some college education.

Men characterized as having high gender role discrepancy and high discrepancy stress reported that they partook in assaults causing injury 348 percent more than men with low discrepancy stress, the researchers said.

“These findings suggest prevention of discrepancy stress may likewise prevent acts of violence with the greatest consequences and costs to the victim, offender and society,” the researchers wrote in the study.

Although there was a strong association between perceptions about masculinity and propensity to violence, there was no association between discrepancy stress and the average daily use of alcoholand drugs, the researchers found. However, men who felt less masculine and were not worried about it were the least likely to report violence or driving while intoxicated.

The researchers suggest that efforts to reduce men’s risky behavior should focus on how men internalize society's masculinity standards, and how these standards can cause stress in boys and men.

The findings also show that different kinds of men — those who feel they are very masculine and those who don’t see themselves as masculine enough and are upset about it, for instance — may need different types of intervention strategies, Reidy told Live Science.

Elizabeth Goldbaum is on Twitter. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.