Chapter 8. Hormones and Sex

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By Debra W. Soh The reasons behind why people are gay, straight, or bisexual have long been a source of public fascination. Indeed, research on the topic of sexual orientation offers a powerful window into understanding human sexuality. The Archives of Sexual Behavior recently published a special edition devoted to research in this area, titled “The Puzzle of Sexual Orientation.” One study, conducted by scientists at the University of Lethbridge in Alberta, Canada, offers compelling, cross-cultural evidence that common genetic factors underlie same-sex, sexual preference in men. In southern Mexico, individuals who are biologically male and sexually attracted to men are known as muxes. They are recognized as a third gender: Muxe nguiiu tend to be masculine in their appearance and behavior, while muxe gunaa are feminine. In Western cultures, they would be considered gay men and transgender women, respectively. Several correlates of male androphilia — biological males who are sexually attracted to men — have been shown across different cultures, which is suggestive of a common biological foundation among them. For example, the fraternal birth order effect—the phenomenon whereby male androphilia is predicted by having a higher number of biological older brothers—is evident in both Western and Samoan cultures. Interestingly, in Western society, homosexual men, compared with heterosexual men, tend to recall higher levels of separation anxiety — the distress resulting from being separated from major attachment figures, like one’s primary caregiver or close family members. Research in Samoa has similarly demonstrated that third-gender fa’afafine—individuals who are feminine in appearance, biologically male, and attracted to men—also recall greater childhood separation anxiety when compared with heterosexual Samoan men. Thus, if a similar pattern regarding separation anxiety were to be found in a third, disparate culture—in the case, the Istmo region of Oaxaca, Mexico—it would add to the evidence that male androphilia has biological underpinnings. © 2017 Scientific American

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 23540 - Posted: 04.26.2017

By CATHERINE SAINT LOUIS In her 30s, Sophie Marat, now 42, used to record herself reading poetry aloud, then play it back to hear if she sounded like a woman. Ms. Marat, who is transgender, had spent years trying to remake her voice in private by speaking in a higher pitch but ultimately felt that her efforts were hopeless. “I was feeling like changing my voice to match my gender identity was almost impossible,” she said. “It was terrible.” Ms. Marat’s transition from male to female has been a gradual evolution. She had come out to friends and family back home in Mexico, then began to wear skirts to work as a software engineer in Manhattan. Still, her confidence would falter with everyday tasks like ordering takeout. “It was really painful to speak on the phone,” she said, “because they would reply, ‘O.K., sir.’” That was before she started her weekly sessions with a voice therapist at New York University’s speech-language-hearing clinic, one of a growing number of programs that cater to transgender clients seeking to retrain their voices. Just as some transgender women and men choose to take hormones or have surgery, or choose neither, some seek to feminize or masculinize their voices. Many say they want a voice that matches their appearance or that the change allows them to escape unwanted attention. There’s also a growing recognition among health professionals who have transgender patients that altering one’s voice can improve quality of life and reduce distress. After eight months, she had raised her pitch, worked on moving her resonance forward and finishing phrases with an open ending, rather than bluntly. “This isn’t just a sidebar,” said Sandy Hirsch, a Seattle-based speech language pathologist who was a co-author of the pioneering textbook on transgender voice and communication therapy. “It’s an integral part of care for transgender people as they transition.” © 2017 The New York Times Company

Keyword: Sexual Behavior; Language
Link ID: 23539 - Posted: 04.26.2017

By Lauren Gravitz, Connor was diagnosed with autism early — when he was just 18 months old. His condition was already obvious by then. “He was lining things up, switching lights on and off, on and off,” says his mother, Melissa. He was bright, but he didn’t speak much until age 3, and he was easily frustrated. Once he started school, he couldn’t sit still in class, called out answers without raising his hand and got visibly upset when he couldn’t master a math concept or a handwriting task quickly enough. “One time, he rolled himself up into the carpet like a burrito and wouldn’t come out until I got there,” Melissa recalls. (All families in this story are identified by first name only, to protect their privacy.) Connor was prescribed his first psychiatric drug, methylphenidate (Ritalin), at age 6. That didn’t last long, but when he was 7, his parents tried again. A psychiatrist suggested a low dose of amphetamine and dextroamphetamine (Adderall), a stimulant commonly used to treat attention deficit hyperactivity disorder (ADHD). The drug seemed to improve his time at school: He was able to sit still for longer periods of time and focus on what his teachers were saying. His chicken-scratch handwriting became legible. Then, it became neat. Then perfect. And then it became something Connor began to obsess over. “We were told that these are the gives and takes; if it’s helping him enough to get through school, you have to decide if it’s worth it,” Melissa says. It was worth it — for a while. © 2017 Scientific American

Keyword: Autism
Link ID: 23531 - Posted: 04.25.2017

Paula Span “During the past four weeks, have you been tired? Been exhausted? Had difficulty getting motivated to do anything at all?” These questions — which a substantial chunk of the population probably could answer in the affirmative — appeared on a questionnaire used in a major European study published recently in The New England Journal of Medicine. The authors were researching the effectiveness of a drug that is widely, if controversially, used to treat older adults with subclinical hypothyroidism, better known as a slightly underactive thyroid. So many Americans take that medication — levothyroxine (brand name Synthroid) — that it topped the list of prescription drugs dispensed in the United States in 2015, according to the research firm QuintilesIMS Institute. With 121 million prescriptions annually, levothyroxine outpaced statins, blood pressure meds — and everything else. A Johns Hopkins survey published last year found that more than 15 percent of older Americans were taking it. So you’d think these study results would come as shocking news: The European team reported that in older people with mild hypothyroidism, the drug had no significant effect on symptoms. At all. Instead, the results bolstered what a number of geriatricians and endocrinologists have suspected for years. “It’s a strong signal that this is an overused medication,” said Dr. Juan Brito, an endocrinologist at the Mayo Clinic. “Some people really need this medicine, but not the vast majority of people who are taking it.” © 2017 The New York Times Company

Keyword: Hormones & Behavior
Link ID: 23522 - Posted: 04.22.2017

Carl Zimmer The oldfield mouse doesn’t seem extraordinary. With soulful black eyes and tiny teacup ears, the rodent lives a humdrum life scurrying about meadows and beaches in the Southeast. But field biologists have long known that when it comes to sex and family life, this mouse is remarkable: Peromyscus polionotus is monogamous — an exception among mammals — and a solicitous parent. Fathers and mothers will dig burrows together and build elaborate nests when pups are on the way; after they’re born, the father will help tend to the pups, retrieving them when they fall out of the nest, licking them, and huddling to keep them warm. In a pioneering study published on Wednesday in the journal Nature, researchers at Harvard University identified a genetic basis for this distinctive behavior. It is the first time that scientists have linked DNA to variations in parenting habits among mammals. Dieter Lukas, an evolutionary biologist at the University of Cambridge who was not involved in the research, hailed the study as a sophisticated tour de force, saying that uncovering these links “is like designing a tool to follow individual threads through a large colorful tapestry.” The findings may one day help scientists make sense of how human couples bond and care for their children. Mammals share many of the genes governing the production of hormones and neurotransmitters in the brain. Variations in how they function may explain why most species are promiscuous, why a few are monogamous — and why some, like humans, are somewhere in between. “We can go from the bottom up and build our knowledge base, and then ask questions about human biology,” said Gene E. Robinson, a biologist at the University of Illinois who was not involved in the new work. © 2017 The New York Times Company

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 23516 - Posted: 04.20.2017

by Claire Lehmann and Debra W Soh “Neurosexism,” “populist science,” “neurotrash,” the problem with using terms like these to describe scientific investigations of sex differences is that their use may be interpreted as hostile. “Not fair!” claim the espousers of these terms, who argue that they only ever use such terms for pseudoscience and media distortions, not robust and replicable studies. In a recent op-ed for The Guardian, Cordelia Fine—the author who coined the term “neurosexism”—together with Rebecca Jordan-Young, argue that they have never been prima facie opposed to sex differences research. Their only concern is that of scientific rigour. In 2005, the British philosopher Nicholas Shackel proposed the term “Motte and Bailey Doctrine” for this type of argumentative style. Taking the name of the castle fortification, the “motte” is strong and is built high on an elevated patch of land and is easy to defend. By contrast, the “bailey” is built on lower, more exposed ground, and is much more difficult to defend from attacks. Shackel used this metaphor to describe a common rhetorical trap used by postmodern academics, where a controversial proposition is put forward (a “bailey”) but is then switched for an uncontroversial one (a “motte”) when faced with criticism. In this case, the controversial position that has been proposed by authors such as Fine and Jordan-Young is that the scientific investigation of sex differences reinforce and legitimize harmful and sexist stereotypes about women. The uncontroversial proposition is that their concern is simply one of “[ensuring] the [maximum possible contribution] of neuroimaging research.” © 2017 Quillette

Keyword: Sexual Behavior
Link ID: 23507 - Posted: 04.19.2017

Laura Sanders Soon after systems biologist Juergen Hahn published a paper describing a way to predict whether a child has autism from a blood sample, the notes from parents began arriving. “I have a bunch of parents writing me now who want to test their kids,” says Hahn, of Rensselaer Polytechnic Institute in Troy, N.Y. “I can’t do that.” That’s because despite their promise, his group’s results, reported March 16 in PLOS Computational Biology, are preliminary — nowhere close to a debut in a clinical setting. The test will need to be confirmed and repeated in different children before it can be used to help diagnose autism. Still, the work of Hahn and colleagues, along with other recent papers, illustrates how the hunt for a concrete biological signature of autism, a biomarker, is gaining speed. Currently, pediatricians, child psychologists and therapists rely on behavioral observations and questionnaires, measures with limitations. Barring genetic tests for a handful of rare mutations, there are no blood draws, brain scans or other biological tests that can reveal whether a child has — or will get — autism. Objective tests would be incredibly useful, helping provide an early diagnosis that could lead to therapy in the first year of life, when the brain is the most malleable. A reliable biomarker might also help distinguish various types of autism, divisions that could reveal who would benefit from certain therapies. And some biomarkers may reveal a deeper understanding of how the brain normally develops. |© Society for Science & the Public 2000 - 2017

Keyword: Autism; Brain imaging
Link ID: 23479 - Posted: 04.11.2017

By Michael Price Do the anatomical differences between men and women—sex organs, facial hair, and the like—extend to our brains? The question has been as difficult to answer as it has been controversial. Now, the largest brain-imaging study of its kind indeed finds some sex-specific patterns, but overall more similarities than differences. The work raises new questions about how brain differences between the sexes may influence intelligence and behavior. For decades, brain scientists have noticed that on average, male brains tend to have slightly higher total brain volume than female ones, even when corrected for males’ larger average body size. But it has proved notoriously tricky to pin down exactly which substructures within the brain are more or less voluminous. Most studies have looked at relatively small sample sizes—typically fewer than 100 brains—making large-scale conclusions impossible. In the new study, a team of researchers led by psychologist Stuart Ritchie, a postdoctoral fellow at the University of Edinburgh, turned to data from UK Biobank, an ongoing, long-term biomedical study of people living in the United Kingdom with 500,000 enrollees. A subset of those enrolled in the study underwent brain scans using MRI. In 2750 women and 2466 men aged 44–77, Ritchie and his colleagues examined the volumes of 68 regions within the brain, as well as the thickness of the cerebral cortex, the brain’s wrinkly outer layer thought to be important in consciousness, language, memory, perception, and other functions. © 2017 American Association for the Advancement of Science

Keyword: Sexual Behavior; Brain imaging
Link ID: 23478 - Posted: 04.11.2017

By Andy Coghlan “PRENATAL exposure to progesterone affects sexual orientation in humans”. A bold and unequivocal-sounding title for a scientific paper. And certainly important if true. But is it? The study claimed to show that women given extra progesterone during pregnancy, routinely prescribed to prevent miscarriage, bleeding or premature delivery, have children who are “29 per cent more likely” to later identify as bisexual. It would be a landmark finding, allowing us to also ground in biology the established social science contention that sexuality has more dimensions than straight and gay. We suspected that exposing a fetus to strong hormones can shape sexual orientation. But there are no animal models of sexual orientation, and doing this kind of experiment in humans would be deeply unethical. The next best thing would be a retrospective analysis looking at a birth cohort exposed to a specific hormone “in the wild”. And that’s what this study did. June Reinisch of the Kinsey Institute in Indiana and her colleagues trawled a public database containing records of more than 9000 pregnancies in Denmark between 1959 and 1961. They identified women who were given a progesterone-mimicking hormone by the trade name lutocyclin to prevent miscarriage. Lutocyclin did seem to have mild effects on sexual orientation: later in life, exposed individuals were five times more likely to self-identify as non-heterosexual, and were more likely to report relationships with the same sex, than unexposed controls. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior
Link ID: 23477 - Posted: 04.11.2017

Cordelia Fine and Rebecca Jordan-Young At a time when both science and feminism are under attack, there are welcome signs that neuroscience is showing new openness to critiques of research into sex differences. Mainstream journals increasingly publish studies that reveal how misleading assumptions about the sexes bias the framing of hypotheses, research design and interpretation of findings – and these critiques increasingly come with constructive recommendations, discussions and debates. For example, we, together with other colleagues, made recommendations in the peer-reviewed journal Frontiers in Human Neuroscience on best practice in sex/gender neuroscience. Some of the errors and traps we identified included human neuroimaging studies with small sample sizes, and the common “snapshot” approach, which interprets neural associations with sex as a matter of timeless and universal male and female essences, without taking seriously the fact that biological associations might as easily be the effect of social differences as the cause of them. For example, a study reporting female-male differences in spatial processing should take into account that women and men have different life experiences, on average, that can build such skills – such as practice with aiming at targets that comes from certain kinds of sports and video games. We also expressed concern about studies that draw on and reinforce stereotypes, even as they slip and slide regarding specific predictions about sex differences in the brain, and what findings might mean for how women and men think, feel, and behave.

Keyword: Sexual Behavior
Link ID: 23465 - Posted: 04.08.2017

By JENNIFER MALIA In “Meet Julia,” an episode of “Sesame Street” that will air April 10 on PBS and HBO, Elmo and Abby Cadabby introduce Big Bird to Julia, a new muppet character with autism. Big Bird says, “Hi, Julia, I’m Big Bird. Nice to meet you.” But Julia continues painting without making eye contact or responding to Big Bird. On “60 Minutes,” Big Bird tells Lesley Stahl, who was on the set when “Sesame Street” was filming the new Muppet’s debut, that he thought Julia didn’t like him at first. Elmo then explains, “Julia has autism so sometimes it takes her a little longer to do things.” I can relate. When my daughter started preschool, she would run laps around the perimeter of the fenced-in playground without responding to kids who said “hi” as she passed by. One day, she stopped in her tracks to pick up a jacket that had fallen to the ground, handed it to a girl without saying a word, and continued running. The kids on the playground probably assumed she didn’t like them — just as Big Bird did. Within the past year, my daughter, who is now 3, my 2-year-old son and I were all given diagnoses of autism spectrum disorder because of our repetitive behaviors, obsessive interests, sensory issues and difficulty with social interactions and pragmatic communication skills. My kids are on the mild to moderate part of the spectrum, having language, but not intellectual, impairments. (I also have a 4-year-old daughter who does not have a diagnosis.) Julia gives me hope that my children and their peers will grow up in a world where autism is normalized, rather than stigmatized. Preschoolers are the primary audience for “Sesame Street,” an educational television program where young children watching Julia’s interactions with her peers can learn by example to support autism acceptance. Since one in 68 American children have an autism diagnosis, wider understanding of the condition is valuable for them as well as for their peers. © 2017 The New York Times Company

Keyword: Autism
Link ID: 23462 - Posted: 04.07.2017

Aaron E. Carroll One of the biggest American public health victories of the last decade has been the record low reached in the teenage birthrate. Along with that have been lows in rates for teenage pregnancy and abortion. Most researchers believe that improved access to contraception is a large part of this success. But news continues to focus on the concern that hormone-based contraception — like the pill or the patch — causes depression, and that this should lead us to question its wider use. A more nuanced discussion would consider both the benefits and the harms. This issue drew widespread coverage at the end of last year with a large study published in JAMA Psychiatry. Researchers tracked all women and adolescent females (ages 15 to 34) living in Denmark from 2000 through 2014. The study found that those who used hormonal contraception had significantly higher risks of also taking an antidepressant. The study broke down the increased relative risk for each hormonal method this way: combined oral contraceptives (23 percent), progestogen-only pills (34 percent), the patch (100 percent), vaginal ring (60 percent) and levonorgestrel intrauterine system (40 percent). The risks were highest in adolescents and decreased as women aged. The risks also peaked six months after the start of contraception. Needless to say, many news outlets covered this finding widely. Some portrayed it as shocking new information that should change the way we think about hormonal birth control. Others saw it as a vindication of many women who said for years that birth control had triggered their depression while scientists and doctors ignored them. But we have to acknowledge the limitations of this type of research. It’s not a controlled trial, and it’s impossible to establish causality. Women who choose to have sex could also be more likely to consider antidepressant use. © 2017 The New York Times Company

Keyword: Depression; Sexual Behavior
Link ID: 23439 - Posted: 04.03.2017

Laurel Hamers SAN FRANCISCO — Girls and boys with attention-deficit/hyperactivity disorder don’t just behave differently. Parts of their brains look different, too. Now, researchers can add the cerebellum to that mismatch. For boys, symptoms of the disorder tend to include poor impulse control and disruptive behavior. Girls are more likely to have difficulty staying focused on one task. Studies show that those behavioral differences are reflected in brain structure. Boys with ADHD, for example, are more likely than girls to display abnormalities in premotor and primary motor circuits, pediatric neurologist Stewart Mostofsky of Kennedy Krieger Institute in Baltimore has reported previously. Now, Mostofsky and colleagues have looked at the cerebellum, which plays a role in coordinating movement. He reported the new findings March 25 at the Cognitive Neuroscience Society’s annual meeting in San Francisco. Girls ages 8 to 12 with ADHD showed differences in the volume of various regions of their cerebellum compared with girls without the condition, MRI scans revealed. A similar comparison of boys showed abnormalities, too. But those differences didn’t match what’s seen between girls, preliminary analyses suggest. So far, researchers have looked at 18 subjects in each of the four groups, but plan to quintuple that number in the coming months. |© Society for Science & the Public 2000 - 2017

Keyword: ADHD; Sexual Behavior
Link ID: 23435 - Posted: 04.01.2017

Erin Ross The sex of a sea lamprey may be determined by how fast it grows as a larva. Sex is determined by chromosomes in mammals and by temperature in many reptiles. But for sea lampreys — eel-like creatures that dine on blood — the growth rate of their larvae seems to control whether they are male or female. They are the first creatures known to undergo sex determination in this way. Researchers know next to nothing about sex determination in sea lampreys (Petromyzon marinus) and have long been puzzled by the observation that some adult populations are mostly male, and others female. The fish begin their lives as larvae with undifferentiated sexual organs. After a year or so, they develop gonads, and after a few more years — the timing can vary — they metamorphose into adult sucker-mouthed parasites. A team led by biologist Nick Johnson, at the US Geological Survey in Millersburg, Michigan, identified lamprey habitats in and near streams leading to the Great Lakes. Some areas were productive, with lots of food, whereas others were unproductive sites with little food. After taking measures to ensure no wild lamprey were present, they released between 1,500 and 3,000 wire-tagged larval lamprey into each of the study sites. The researchers recaptured the tagged lamprey and checked their sex after the larvae had metamorphosed into adults and migrated upstream. They found that lamprey in productive streams with lots of food were larger, reached maturity earlier and were more likely to be female. But in unproductive sites, smaller, male lamprey dominated, Johnson’s team reports in a paper published on 29 March in Proceedings of the Royal Society B1. © 2017 Macmillan Publishers Limited

Keyword: Sexual Behavior; Evolution
Link ID: 23427 - Posted: 03.30.2017

By Catherine Offord | Recognizing when you’re singing the right notes is a crucial skill for learning a melody, whether you’re a human practicing an aria or a bird rehearsing a courtship song. But just how the brain executes this sort of trial-and-error learning, which involves comparing performances to an internal template, is still something of a mystery. “It’s been an important question in the field for a long time,” says Vikram Gadagkar, a postdoctoral neurobiologist in Jesse Goldberg’s lab at Cornell University. “But nobody’s been able to find out how this actually happens.” Gadagkar suspected, as others had hypothesized, that internally driven learning might rely on neural mechanisms similar to traditional reward learning, in which an animal learns to anticipate a treat based on a particular stimulus. When an unexpected outcome occurs (such as receiving no treat when one was expected), the brain takes note via changes in dopamine signaling. So Gadagkar and his colleagues investigated dopamine signaling in a go-to system for studying vocal learning, male zebra finches. First, the researchers used electrodes to record the activity of dopaminergic neurons in the ventral tegmental area (VTA), a brain region important in reward learning. Then, to mimic singing errors, they used custom-written software to play over, and thus distort, certain syllables of that finch’s courtship song while the bird practiced. “Let’s say the bird’s song is ABCD,” says Gadagkar. “We distort one syllable, so it sounds like something between ABCD and ABCB.” © 1986-2017 The Scientist

Keyword: Hearing; Sexual Behavior
Link ID: 23426 - Posted: 03.30.2017

By Kate Yandell In a 1971 paper published in Science, biologist Roger Payne, then at Rockefeller University, and Scott McVay, then an administrator at Princeton University, described the “surprisingly beautiful sounds” made by humpback whales (Megaptera novaeangliae; Science, 173:585-97). Analyzing underwater recordings made by a Navy engineer, the duo found that these whale sounds were intricately repetitive. “Because one of the characteristics of bird songs is that they are fixed patterns of sounds that are repeated, we call the fixed patterns of humpback sounds ‘songs,’” they wrote. OCEAN SONGS: Humpback whales make diverse, broadband sounds that travel miles through the ocean. Their function, however, remains somewhat murky.PLOS ONE, dx.doi.org/10.1371/journal.pone.0079422, 2013 It’s now clear that, in addition to simpler calls, several baleen whale species—including blue, fin, and bowhead—make series of sounds known as song. Humpback song is the most complex and by far the best studied. Units of humpback songs form phrases, series of similar phrases form themes, and multiple themes form songs. All the males in a given population sing the same song, which evolves over time. When whale groups come into contact, songs can spread. But why do whales sing? “The short answer is, we don’t know,” says Alison Stimpert, a bioacoustician at Moss Landing Marine Laboratories in California. Humpback songs are only performed by males and are often heard on breeding grounds, so the dominant hypothesis is that these songs are a form of courtship. The quality of a male’s performance could be a sign of his fitness, for example. But female whales do not tend to approach singing males. Alternatively, whale researchers have proposed that the male whales sing to demarcate territory or to form alliances with other males during mating season. © 1986-2017 The Scientist

Keyword: Sexual Behavior; Hearing
Link ID: 23419 - Posted: 03.29.2017

By RONI CARYN RABIN Television ads for “low T” have sparked a rise in the use of testosterone gels, patches and injections by older men in recent years, according to a new report. But anyone hoping that a dose of testosterone will provide an easy antidote for sagging muscles, flagging energy and a retiring sex drive may find the results of recent government studies of the sex hormone sobering. The latest clinical trials, published over the past year, are the first rigorous ones to assess the potential beneficial effects of testosterone treatment for older men with abnormally low levels of the hormone. Scientists followed 790 men age 65 and older who had blood testosterone levels below 275 nanograms per deciliter of blood, well below the average for healthy young men and lower than would be expected with normal aging. The men also had symptoms reflecting their low hormone levels, like loss of sex drive. Half the participants were treated with testosterone gel, and half were given a placebo gel. The studies reported mixed results, finding that over the yearlong study period, testosterone therapy corrected anemia, or low levels of red blood cells, which can cause fatigue, and increased bone density. But a study to see if testosterone improved memory or cognitive function found no effects. Meanwhile, a red flag warning of possible risks to the heart emerged from the studies: Imaging tests found a greater buildup of noncalcified plaque in the coronary arteries of men treated with testosterone for a year, an indicator of cardiac risk, compared with those who were given a placebo gel. The findings of plaque were not a complete surprise; many reports have tied testosterone use to an increase in heart attacks, and the Food and Drug Administration already requires testosterone products to carry warnings of an increased risk of heart attacks and stroke (men at high risk of cardiovascular disease were not allowed to participate in the latest trials). But observational studies, which are weaker, have yielded mixed results over all, with one study published last month finding that men taking testosterone actually had fewer heart problems. © 2017 The New York Times Company

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 23413 - Posted: 03.28.2017

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

By Daisy Yuhas, Spectrum on March 22, 2017 In children with a deletion on chromosome 22, having autism does not boost the risk of developing schizophrenia later in life, according to a new study1. The children in the study have 22q11.2 deletion syndrome, which is linked to a 25-fold increase in the risk of developing a psychotic condition such as schizophrenia. A deletion in the region is also associated with an increased risk of autism. Some researchers have suggested that the relatively high autism prevalence in this population is the result of misdiagnoses of early signs of schizophrenia. The new findings, published 21 January in Schizophrenia Research, support an alternate theory: Autism and schizophrenia are independent outcomes of the same genetic syndrome. If there is a relationship between the two conditions, “that can only be a very small, probably negligible effect,” says lead investigator Jacob Vorstman, assistant professor of child psychiatry and genetics at the University Medical Center Utrecht in the Netherlands. The new findings could help guide clinical care, says Opal Ousley, assistant professor of psychiatry at the Emory Autism Center in Atlanta. If prenatal testing picks up the 22q11.2 deletion, for instance, clinicians could discuss the risk of both autism and schizophrenia with parents. © 2017 Scientific American

Keyword: Autism; Schizophrenia
Link ID: 23393 - Posted: 03.23.2017

By Jill Serjeant NEW YORK (Reuters) - Long-running children's television show "Sesame Street" is welcoming a new kid to the block - a Muppet with autism called Julia. A redhead who loves to sing and remembers the words to lots of songs, Julia will debut on the show for preschoolers on April 10 after a five-year outreach effort to families and experts on autism, Sesame Workshop said on Monday. "For years, families of children with autism have asked us to address the issue," Dr. Jeanette Betancourt, senior vice president of U.S. social impact at the nonprofit Sesame Workshop, said in a statement. One in 68 American children is currently diagnosed with autism, according to the Centers for Disease Control and Prevention, an increase of some 119 percent since 2000. Autism is a developmental disorder present from early childhood, characterized by difficulty in communicating and forming relationships with other people and in using language and abstract concepts Stacey Gordon, the puppeteer who will perform the role of Julia, and Christine Ferraro who wrote her part, both have family members who are on the autism spectrum. "It's important for kids without autism to see what autism can look like," Gordon told the CBS show "60 Minutes" in a preview on Sunday. "Had my son's friends been exposed to his behaviors through something that they had seen on TV before they experienced them in the classroom, they might not have been frightened. They might not have been worried when he cried. They would have known that he plays in a different way and that that's okay," she added. © 2017 Scientific American

Keyword: Autism
Link ID: 23387 - Posted: 03.22.2017