Chapter 12. Sex: Evolutionary, Hormonal, and Neural Bases

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By Sam Wong It takes brains to choose a good partner. In one of the first experiments to look at the cognitive demands of choosing a mate, female guppies with big brains showed a preference for more colourful males, while those with smaller brains showed no preference. In guppies, like most animals, females are choosy about who to mate with, since they invest more in their offspring than males, which don’t help care for them. They tend to prefer males with striking colour patterns and big tails, traits that have been linked to good foraging ability and health. By choosing a male with these qualities, female guppies give their offspring a good chance of inheriting the same useful traits. Despite this, females often go on to make different choices. Alberto Corral López and colleagues at Stockholm University wanted to find out if brain size could account for this. Corral López and his team tested 36 females bred to have large brains, 36 bred to have small brains, and 16 females similar to guppies found in the wild. Previous studies have shown that large-brained guppies perform better in cognitive tests, suggesting that they are smarter. Each female was given the opportunity to associate with two males, one more colourful than the other. Females are known to spend more time close to males they would prefer to mate with, so the team timed how long they spent with each male. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Evolution
Link ID: 23394 - Posted: 03.23.2017

Cris Ledón-Rettig Picture a lion: The male has a luxuriant mane, the female doesn’t. This is a classic example of what biologists call sexual dimorphism – the two sexes of the same species exhibit differences in form or behavior. Male and female lions pretty much share the same genetic information, but look quite different. We’re used to thinking of genes as responsible for the traits an organism develops. But different forms of a trait – mane or no mane – can arise from practically identical genetic information. Further, traits are not all equally sexually dimorphic. While the tails of peacocks and peahens are extremely different, their feet, for example, are pretty much the same. Understanding how this variation of form – what geneticists call phenotypic variation – arises is crucial to answering several scientific questions, including how novel traits appear during evolution and how complex diseases emerge during a lifetime. So researchers have taken a closer look at the genome, looking for the genes responsible for differences between sexes and between traits within one sex. The key to these sexually dimorphic traits appears to be a kind of protein called a transcription factor, whose job it is to turn genes “on” and “off.” In our own work with dung beetles, my colleagues and I are untangling how these transcription factors actually lead to the different traits we see in males and females. A lot of it has to do with something called “alternative gene splicing” – a phenomenon that allows a single gene to encode for different proteins, depending on how the building blocks are joined together. © 2010–2017, The Conversation US, Inc.

Keyword: Sexual Behavior; Evolution
Link ID: 23380 - Posted: 03.21.2017

By Jenny Rood To human ears, the trilling of birdsong ranks among nature’s most musical sounds. That similarity to human music is now inspiring researchers to apply music theory to avian vocalizations. For example, zebra finch neurobiologist Ofer Tchernichovski of the City University of New York, together with musician and musicologist Hollis Taylor, recently analyzed the song of the Australian pied butcherbird (Cracticus nigrogularis) and found an inverse relationship between motif complexity and repetition that paralleled patterns found in human music (R Soc Open Sci, 3:160357, 2016). Tchernichovski’s work also suggests that birds can perceive rhythm and change their calls in response. Last year, he and colleague Eitan Globerson, a symphony conductor at the Jerusalem Academy of Music and Dance as well as a neurobiologist at Bar Ilan University in Israel, demonstrated that zebra finches, a vocal learning species, adapt their innate calls—as opposed to learned song—to avoid overlapping with unusual rhythmic patterns produced by a vocal robot (Curr Biol, 26:309-18, 2016). The researchers also found that both males and females use the brain’s song system to do this, although females do not learn song. But these complexities of birdsong might be more comparable to human speech than to human music, says Henkjan Honing, a music cognition scientist at the University of Amsterdam. Honing’s research suggests that some birds don’t discern rhythm well. Zebra finches, for example, seem to pay attention to pauses between notes on short time scales but have trouble recognizing overarching rhythmic patterns—one of the key skills thought necessary for musical perception (Front Psychol, doi:10.3389/fpsyg.2016.00730, 2016). © 1986-2017 The Scientist

Keyword: Animal Communication; Hearing
Link ID: 23368 - Posted: 03.17.2017

By Timothy Revell Who would you get to observe differences in how men, women and children interact? A robot in a fur-lined hat, of course. Experiments using a robotic head, called Furhat, aimed to uncover inequalities in people’s participation when working on a shared activity, and see if a robot could help redress the balance. They revealed that when a woman is paired in conversation with another woman, she speaks more than if paired with a man. And two men paired together speak less than two women. But this only holds for adults. “Surprisingly, we didn’t find this same pattern for boys and girls. Gender didn’t make much difference to how much children speak,” says Gabriel Skantze at the KTH Royal Institute of Technology in Stockholm, Sweden, who is also one of the robot’s creators. Furhat interacted with 540 visitors at the Swedish National Museum of Science and Technology over nine days. Two people at a time would sit at an interactive table with a touchscreen opposite the robot. They were asked to play a game that involved sorting a set of virtual picture cards, such as arranging images of historical inventions in chronological order. The people worked with the robot to try to solve the task. During this time, the robot’s sensors tracked how long each person spoke for. “This turned out to be a really nice opportunity to study the differences between men and women, and adults and children,” says Skantze. © Copyright Reed Business Information Ltd.

Keyword: Language; Sexual Behavior
Link ID: 23367 - Posted: 03.17.2017

By Michael Price The objects and people children play with as early as toddlerhood may provide clues to their eventual sexual orientation, reveals the largest study of its kind. The investigation, which tracked more than 4500 kids over the first 15 years of their lives, seeks to answer one of the most controversial questions in the social sciences, but experts are mixed on the findings. “Within its paradigm, it’s one of the better studies I’ve seen,” says Anne Fausto-Sterling, professor emerita of biology and gender studies at Brown University. The fact that it looks at development over time and relies on parents’ observations is a big improvement over previous studies that attempted to answer similar questions based on respondents’ own, often unreliable, memories, she says. “That being said … they’re still not answering questions of how these preferences for toys or different kinds of behaviors develop in the first place.” The new study builds largely on research done in the 1970s by American sex and gender researcher Richard Green, who spent decades investigating sexuality. He was influential in the development of the term “gender identity disorder” to describe stress and confusion over one’s sex and gender, though the term—and Green’s work more broadly—has come under fire from many psychologists and social scientists today who say it’s wrong to label someone’s gender and sexuality “disordered.” In the decades since, other studies have reported that whether a child plays along traditional gender lines can predict their later sexual orientation. But these have largely been criticized for their small sample sizes, for drawing from children who exhibit what the authors call “extreme” gender nonconformity, and for various other methodological shortcomings. © 2017 American Association for the Advancement of Science

Keyword: Sexual Behavior; Development of the Brain
Link ID: 23347 - Posted: 03.11.2017

If I was the late Andy Rooney, I’d say “You know what really bothers me? When science shows some facts about nature, and then someone rejects those facts because they’re inconvenient or uncomfortable for their ideology.” Indeed, when people ignore such inconvenient truths, it not only makes their cause look bad, but can produce palpable harm. Case in point: the damage that the Russian charlatan-agronomist Lysenko did to Soviet agriculture under Stalin. Rejecting both natural selection and modern genetics, Lysenko made all sorts of wild promises about improving Soviet agriculture based on bogus treatment of plants that would supposedly change their genetics. It not only didn’t work, failing to relieve Russia of its chronic famines, but Lyesnko’s Stalin-supported resistance to modern (“Western”) genetics led to the imprisonment and even the execution of really good geneticists and agronomists like Niklolia Vavilov. The ideological embrace of an unevidenced but politically amenable view of science set back Russian genetics for decades. Other cases in point: the denial of evolution by creationists, and of anthropogenic global warming by conservatives. I needn’t belabor these. But the opposition to research on group and sex differences continues. One of its big exponents is the author Cordelia Fine, who has written two books with the explicit aim of showing that there are no reliably accepted evolved and biological differences in behavior between men and women. I read her first book, Delusions of Gender, and found it a mixed bag: some of her targets did indeed do bad science, and she properly called them out; but the book was also tendentious, and wasn’t objective about other studies. I’m now about to read her second book, Testosterone Rex: Myths of Sex, Science, and Society. Judging from the reviews, which have been positive, it’s just as much a polemic as the first book, and has an ideological aim.

Keyword: Sexual Behavior; Evolution
Link ID: 23336 - Posted: 03.10.2017

By Lindzi Wessel You may have seen the ads: Just spray a bit of human pheromone on your skin, and you’re guaranteed to land a date. Scientists have long debated whether humans secrete chemicals that alter the behavior of other people. A new study throws more cold water on the idea, finding that two pheromones that proponents have long contended affect human attraction to each other have no such impact on the opposite sex—and indeed experts are divided about whether human pheromones even exist. The study, published today in Royal Society Open Science, asked heterosexual participants to rate opposite-sex faces on attractiveness while being exposed to two steroids that are putative human pheromones. One is androstadienone (AND), found in male sweat and semen, whereas the second, estratetraenol (EST), is in women’s urine. Researchers also asked participants to judge gender-ambiguous, or “neutral,” faces, created by merging images of men and women together. The authors reasoned that if the steroids were pheromones, female volunteers given AND would see gender-neutral faces as male, and male volunteers given EST would see gender-neutral faces as female. They also theorized that the steroids corresponding to the opposite sex would lead the volunteers to rate opposite sex faces as more attractive. That didn’t happen. The researchers found no effects of the steroids on any behaviors and concluded that the label of “putative human pheromone” for AND and EST should be dropped. “I’ve convinced myself that AND and EST are not worth pursuing,” says the study’s lead author, Leigh Simmons, an evolutionary biologist at the University of Western Australia in Crawley. © 2017 American Association for the Advancement of Science.

Keyword: Chemical Senses (Smell & Taste); Hormones & Behavior
Link ID: 23327 - Posted: 03.08.2017

Nicola Davis The mystery of why sheep get horny in the winter might have been solved, according to new research. Scientists say they have uncovered the key to the mechanism by which changes in the length of the day prompt certain animals to begin breeding, trigger the growth of horns and even change the thickness of their coat. The findings, the team add, could help farmers tinker with the timing of the lambing season. “Now we know what that link is we can start to understand how it can be controlled,” said David Bates, professor of oncology at the University of Nottingham and co-author of the research. It has long been known that changes in animals’ fertility over the seasons is linked to melatonin – a hormone released at night from the pineal gland in the brain. This hormone acts on another gland, the pituitary, affecting the levels of various sex hormones it produces. With the onset of fertility in sheep linked to longer periods of melatonin production, winter is the season for ovine Casanovas. But there is a puzzle. The region of the pituitary gland that detects melatonin is separate to the region that produces sex hormones. As a result, scientists had been baffled as to how melatonin ends up affecting the onset of fertility. “No-one has been able to find what the link is,” said Bates. Now Bates and colleagues from the University of Bristol say they have the answer. Writing in the journal PNAS, the team reveal the missing link is a protein, known as vascular endothelial growth factor, which is made in the region of the pituitary gland that detects melatonin. © 2017 Guardian News and Media Limited

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 23322 - Posted: 03.07.2017

By The Scientist Staff For thousands of years, people have appreciated birdsong as one of nature’s most melodic sounds. And for at least a few centuries, researchers have been talking about—and analyzing— birdsong, some attaching the label “music” to the avian behavior. In the mid-17th century, for example, German scholar Athanasius Kircher transcribed bird song with musical notation. Whether singing avian species hear their calls in a musical sense is, of course, anybody’s guess. But still today, it’s fairly uncontroversial to speak about bird vocalizations using terms such as “song” and “music.” Around the animal kingdom, several nonavians also produce sounds that are sometimes discussed using a musical vocabulary. Whale songs echo through the ocean for hundreds of miles, while frogs and crickets chorus on warm summer nights throughout much of the world. The stringency of the criteria for earning a label such as song varies by taxon, however. Birds, whales, mice, and even bats have a vocal repertoire that includes songs and simpler calls, while any insect or fish that produces sound for the sake of communication is considered, at least by some, to be “singing”—though no scientist seriously compares these species’ chirps and grunts to birdsong. Semantics aside, more and more tonal or cadenced animal communication signals are attracting the attention of researchers. Technological advancements have enabled the study of mouse and bat calls that are broadcast in the ultrasonic range, as well as of the love songs of fruit flies, which vibrate their wings to produce sound within the frequency range of human hearing, but do so a million times more quietly than our ears can detect. And research continues to delve into the musical skills of diverse bird species that have long been recognized for their singing prowess, confirming that there is an overlap between the genes and brain areas involved in bird and human vocal learning. © 1986-2017 The Scientist

Keyword: Sexual Behavior; Animal Communication
Link ID: 23321 - Posted: 03.07.2017

by Laura Sanders Amid a flurry of cabinet appointments and immigration policies, the Trump administration has announced one thing it will not do: pursue policies that protect transgender children in public schools. The Feb. 22 announcement rescinds Obama administration guidelines that, among other protections, allow transgender kids to use bathrooms and participate in sports that correspond with their genders, and to be called by their preferred names and pronouns. In a Feb. 23 news briefing, White House press secretary Sean Spicer said that this is a states’ rights issue. “States should enact laws that reflect the values, principles, and will of the people in their particular state,” he said. “That's it, plain and simple.” But this “plain and simple” move could be quite dangerous, even deadly, science suggests. Transgender children, who are born one biological sex but identify as the other, already face enormous challenges as they move through a society that often doesn’t understand or accept them. Consider this: Nearly half (46.5 percent) of young transgender adults have attempted suicide at some point in their lives, a recent survey of over 2,000 people found. Nearly half. For comparison, the attempted suicide rate among the general U.S. population is estimated to be about 4.6 percent. What’s more, a 2015 study in the Journal of Adolescent Health found that transgender youth are two to three times as likely as their peers to suffer from depression and anxiety disorders, or to attempt suicide or harm themselves. These troublesome stats, based on a sample of 180 transgender children and young adults in Boston ages 12 to 29, applied equally to those who underwent male-to-female transitions and those who underwent female-to-male transitions. © Society for Science & the Public 2000 - 2017.

Keyword: Sexual Behavior; Depression
Link ID: 23297 - Posted: 03.01.2017

By Joshua A. Krisch When Kathleen Gardiner first encountered female mice with Down syndrome, she was surprised to find that the rodents’ brains showed unexpected abnormalities. Gardiner, a neuroscientist at the University of Colorado School of Medicine in Aurora, knew that trisomic male mice typically had perturbed protein levels in their hippocampuses. But these trisomic female mice showed the most serious changes in their cerebellums. “Right away, there’s a brain region sex difference,” Gardiner said. “It’s very interesting to ponder the fact that this could lead to sex differences in the learning, memory, or behavioral abnormalities associated with [Down syndrome].” Although Gardiner recognized that differences between mouse sexes would not necessarily translate into sex differences in humans, she considered the potential implications for clinical studies on Down syndrome therapies. “If we find that males or females are differing not only in their baseline impairment, but in their response to drugs, we need to know that,” she said. “We could be missing a big piece of information that could lead to better or different clinical trials.” Indeed, sex differences in model organisms are becoming increasingly apparent. Studies have shown sex differences in mice can affect cardiovascular health, liver disease, and cancer risk. Many of these studies are now published in Biology of Sex Differences, where Gardiner’s own work on the trisomic female mice appeared. © 1986-2017 The Scientist

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 23280 - Posted: 02.25.2017

By Carolyn Gramling Trilobites—three-sectioned, crablike critters that dominated the early Paleozoic—are so abundant that they have become the gateway fossil for most collectors. But paleontologists have found little evidence of how the extinct arthropods reproduced—until now. Researchers studying a fossil specimen of the trilobite Triarthrus eatoni spotted something odd just next to the animal’s head: a collection of small (about 200 micrometers across), round objects (in light blue, above). Those, they determined, are actually eggs—the first time anyone had observed fossil trilobite eggs right next to the critters themselves. The structures were exceptionally well preserved, the eggs and exoskeletons of the trilobites replaced with an iron sulfide ore called pyrite. They came from the Lorraine Group, a rock formation that spans much of the northeastern United States and dates to the Ordovician period (about 485 million to 444 million years ago); it has long been a mecca for trilobite hunters because of the pyritization. The placement of the eggs is suggestive, the researchers report in the March issue of Geology: They hypothesize that trilobites released their eggs and sperm through a genital pore somewhere in the head—much like modern horseshoe crabs do today. One possible reason for the rarity of the find may be that the brooding behavior of T. eatoni was relatively unusual in the trilobite world: The species tended to prefer a harsh, low-oxygen environment, and may have kept a closer eye on their eggs than other trilobite species. But, the authors note, one idea this finding does lay to rest is that trilobites might reproduce via copulation—a titillating but little-regarded hypothesis based on the fact that trilobites are sometimes found clustered on top of one another. Instead, trilobites were most likely spawners—and, in fact, that clustering behavior may be another parallel to horseshoe crabs, which can climb on top of one another in competition to fertilize released eggs. © 2017 American Association for the Advancement of Science

Keyword: Sexual Behavior; Evolution
Link ID: 23279 - Posted: 02.25.2017

Patricia Neighmond Many men over 65 with low testosterone levels say their sense of well-being, not to mention sexual function, isn't what it used to be. That's why some doctors prescribe testosterone replacement. But the effectiveness of testosterone has been controversial. Studies of the risks and benefits have been mixed, and the Food and Drug Administration beefed up its warnings about cardiac side effects of testosterone supplementation in 2015. And the findings of five studies released Tuesday aren't likely to clear up the confusion. They appear in JAMA, the journal of the American Medical Association and JAMA Internal Medicine. The studies are collectively called the Testosterone Trials (TTrials) and they compared a testosterone gel, AndroGel, against a placebo. The results are based on 788 men with below normal levels of testosterone studied at 12 sites across the country over a year. Overall, researchers saw improvements in bone density and bone strength in men who used a testosterone gel, which raised their testosterone to levels seen in younger men. In men with unexplained anemia, testosterone also improved iron levels in the blood. (A reviewer of the study raised questions about whether it was done ethically.) But in men using testosterone who had been reporting memory problems at the start of the study, there were no improvements in memory or cognition. And there were worrisome signs of an increase in the risk of cardiovascular problems. © 2017 npr

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 23267 - Posted: 02.22.2017

By Greta Keenan The ocean might seem like a quiet place, but listen carefully and you might just hear the sounds of the fish choir. Most of this underwater music comes from soloist fish, repeating the same calls over and over. But when the calls of different fish overlap, they form a chorus. Robert McCauley and colleagues at Curtin University in Perth, Australia, recorded vocal fish in the coastal waters off Port Headland in Western Australia over an 18-month period, and identified seven distinct fish choruses, happening at dawn and at dusk. You can listen to three of them here: The low “foghorn” call is made by the Black Jewfish (Protonibea diacanthus) while the grunting call that researcher Miles Parsons compares to the “buzzer in the Operation board game” comes from a species of Terapontid. The third chorus is a quieter batfish that makes a “ba-ba-ba” call. “I’ve been listening to fish squawks, burble and pops for nearly 30 years now, and they still amaze me with their variety,” says McCauley, who led the research. Sound plays an important role in various fish behaviours such as reproduction, feeding and territorial disputes. Nocturnal predatory fish use calls to stay together to hunt, while fish that are active during the day use sound to defend their territory. “You get the dusk and dawn choruses like you would with the birds in the forest,” says Steve Simpson, a marine biologist at the University of Exeter, UK. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Animal Communication
Link ID: 23256 - Posted: 02.21.2017

Elizabeth Eaton A prehistoric marine reptile may have given birth to its young alive. A fossil from South China may be the first evidence of live birth in the animal group Archosauromorpha, scientists report February 14 in Nature Communications. Today Archosauromorpha is represented by birds and crocodiles — which both lay eggs. Whether this fossil really is the first evidence of live birth in Archosauromorpha depends on how another group of semiaquatic animals is classified, says Michael Caldwell, a vertebrate paleontologist with the University of Alberta in Canada. Placement of Choristodera, a now-extinct group that included a freshwater reptile that gave live birth, remains murky, with some researchers putting them with Archosauromorpha and others with a group that includes snakes and lizards. “Our discovery is the first of live birth in reptiles with undoubted archosauromorph affinity,” says Jun Liu, a paleontologist at Hefei University of Technology in China. Researchers have speculated that the biology of archosauromorphs prevented their reproductive traits from evolving, says study coauthor Chris Organ, an evolutionary biologist with Montana State University in Bozeman. This find may disprove that view. “Ancestrally, the science suggests that live birth is not absolutely prohibited,” Organ says. Even though birds and crocodiles haven’t yet evolved to give life birth, this discovery suggests that it’s possible. |© Society for Science & the Public 2000 - 2016

Keyword: Sexual Behavior; Evolution
Link ID: 23230 - Posted: 02.15.2017

Moises Velasquez-Manoff This Valentine’s Day, as you bask in the beauty of your beloved, don’t just thank his or her genes and your good fortune; thank microbes. Research on the microbes that inhabit our bodies has progressed rapidly in recent years. Scientists think that these communities, most of which live in the gut, shape our health in myriad ways, affecting our vulnerability to allergic diseases like hay fever, how much weight we put on, our susceptibility to infection and maybe even our moods. They can also, it seems, make us sexy. Susan Erdman, a microbiologist at M.I.T., calls it the “glow of health.” The microbes you harbor, she argues, can make your skin smooth and your hair shiny; they may even put a spring in your step. She stumbled on the possibility some years ago when, after feeding mice a probiotic microbe originally isolated from human breast milk, a technician in her lab noticed that the animals grew unusually lustrous fur. Further observation of males revealed thick skin bristling with active follicles, elevated testosterone levels and oversize testicles, which the animals liked showing off. Microbes had transformed these animals into rodent heartthrobs. When given to females, the probiotic also prompted deeper changes. Levels of a protein called interleukin 10, which helps to prevent inflammatory disease and ensure successful pregnancy, went up, as did an important hormone called oxytocin. Oxytocin, often called the love hormone, helps mammals bond with one another. Our bodies may release it when we kiss (and mean it), when women breast-feed, even when people hang out with good friends. And the elevated oxytocin Dr. Erdman saw had important effects during motherhood. Some of the mice in her studies were eating a high-fat, high-sugar diet — junk-foody fare that’s known to shift the microbiome into an unhealthy state. Not surprisingly perhaps, mothers that didn’t imbibe the probiotics were less caring and tended to neglect their pups. But mothers that had high oxytocin thanks to the probiotic were nurturing and reared their pups more successfully. © 2017 The New York Times Company

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 23221 - Posted: 02.13.2017

Patti Neighmond It's tough to be a teenager. Hormones kick in, peer pressures escalate and academic expectations loom large. Kids become more aware of their environment in the teen years — down the block and online. The whole mix of changes can increase stress, anxiety and the risk of depression among all teens, research has long shown. But a recent study published in the journal Pediatrics suggests many more teenage girls in the U.S. may be experiencing major depressive episodes at this age than boys. And the numbers of teens affected took a particularly big jump after 2011, the scientists note, suggesting that the increasing dependence on social media by this age group may be exacerbating the problem. Psychiatrist Ramin Mojtabai and colleagues at Johns Hopkins University Bloomberg School of Public Health wanted to know whether rates of depression among teens had increased over the past decade. They analyzed federal data from interviews with more than 172,000 adolescents. Between 2005 and 2014, the scientists found, rates of depression went up significantly — if extrapolated to all U.S. teens it would work out to about a half million more depressed teens. What's more, three-fourths of those depressed teens in the study were girls. The findings are just the latest in a steady stream of research showing that women of all ages experience higher rates of depression compared to men, says psychologist and author Catherine Steiner-Adair. And no wonder, she says — despite gains in employment, education and salary, women and girls are still "continually bombarded by media messages, dominant culture, humor and even political figures about how they look — no matter how smart, gifted, or passionate they are." © 2017 npr

Keyword: Depression; Development of the Brain
Link ID: 23220 - Posted: 02.13.2017

By STEPH YIN If you’re reading this at home, pause and put on a song you can’t resist dancing to. Go on, bop your head to the beat. Let yourself wiggle a bit. Throw in some arms and legs. If you’re reading this at work, maybe imagine these things at your desk. As you’re dancing, pay attention to where and how you’re moving. How much are you swaying your hips? Are your legs moving together or independently of each other? How vigorously are you moving your torso? You should note those movements, because very specific patterns may make some people appear to be better dancers than others. That’s the conclusion of a study published on Thursday in Scientific Reports, in which researchers asked 200 people to rate 39 female dancers. A few features stood out as contributing to higher-quality dance: big hip swings, and the right and left limbs moving independently of one another (which the researchers describe as asymmetric arm and thigh movements). The researchers speculate that those moves serve two purposes for heterosexual women. “One is, they’re showing off their reproductive quality, perhaps their hormonal status, to males,” said Nick Neave, an associate professor of psychology at Northumbria University in England and an author of the paper. “Another is, they’re showing off how good they are to female rivals.” In 2011, the same researchers reported that women preferred certain dance moves by men, especially exaggerated movements in the upper body. In other studies, Dr. Neave and his colleagues have found links between male dance attractiveness and risk-taking, as well as handgrip strength, a marker for overall body strength. “We know that dance moves are signaling strength and vigor in males,” Dr. Neave said. “Now we’re beginning to do the same research with females.” In the study, his team asked 39 female university students in Britain to dance alone to a drum beat. The researchers used a motion-capture system to track the women’s moves. They animated each dancer as an avatar to try to make sure that only the dance movements — and no other physical features — would affect ratings. Then they recruited 57 men and 143 women to watch 15-second clips of the avatars and rate them each on a numeric scale. © 2017 The New York Times Company

Keyword: Sexual Behavior; Evolution
Link ID: 23212 - Posted: 02.10.2017

Having a thicker outer layer of the brain is linked to an increased likelihood of having autism. The cerebral cortex is the wrinkled outer layer of the brain that is responsible for many of our most human traits, including thought, language and consciousness. This layer is typically thicker in men than in women, and its structure has been linked to differences in personality. Now brain scans have shown that women who have a more male-like brain structure are three times more likely to have been diagnosed with autism. The study compared the brains of 98 men and women with high functioning autism with those of 98 people who don’t have autism. These findings provide new insights into the brain’s role in sex differences in autism, according to the team that did the study. Autism is thought to be two to five times more common in men than in women, and some think the condition is caused by having an “extreme male brain”. Journal reference: JAMA Psychiatry, DOI: 10.1001/jamapsychiatry.2016.3990 © Copyright Reed Business Information Ltd.

Keyword: Autism; Sexual Behavior
Link ID: 23202 - Posted: 02.09.2017

by Bethany Brookshire Gender bias works in subtle ways, even in the scientific process. The latest illustration of that: Scientists recommend women less often than men as reviewers for scientific papers, a new analysis shows. That seemingly minor oversight is yet another missed opportunity for women that might end up having an impact on hiring, promotions and more. Peer review is one of the bricks in the foundation supporting science. A researcher’s results don’t get published in a journal until they successfully pass through a gauntlet of scientific peers, who scrutinize the paper for faulty findings, gaps in logic or less-than-meticulous methods. The scientist submitting the paper gets to suggest names for those potential reviewers. Scientific journal editors may contact some of the recommended scientists, and then reach out to a few more. But peer review isn’t just about the paper (and scientist) being examined. Being the one doing the reviewing “has a number of really positive benefits,” says Brooks Hanson, an earth scientist and director of publications at the American Geophysical Union in Washington, D.C. “You read papers differently as a reviewer than you do as a reader or author. You look at issues differently. It’s a learning experience in how to write papers and how to present research.” Serving as a peer reviewer can also be a networking tool for scientific collaborations, as reviewers seek out authors whose work they admired. And of course, scientists put the journals they review for on their resumes when they apply for faculty positions, research grants and awards. |© Society for Science & the Public 2000 - 2017.

Keyword: Attention; Sexual Behavior
Link ID: 23185 - Posted: 02.04.2017