Chapter 8. Hormones and Sex

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By Debra W. Soh If there was a way of telling who in our society is sexually attracted to children, are we entitled to know? A recent study from Georg-August-University Göttingen in Germany suggests that we may need to grapple with this question. Phallometric testing, also known as penile plethysmography, is considered the gold standard in measuring male sexual arousal, and particularly, deviant sexual interests such as pedophilia, which is the sexual interest in prepubescent children, roughly aged 3 to 10. The test involves measuring the volume of blood in the test-taker’s penis using an airtight glass tube (or conversely, measuring penile circumference with a mercury strain gauge) while he is presented with a series of images of children and adults, and audio stories describing a corresponding sexual encounter. Phallometry is commonly used in forensic settings to assess the sexual interests of sex offenders, in order to determine their risk of re-offending. As one can imagine, sex offenders tend not to be forthright about their sexual preferences, which makes phallometry all the more important. It has, however, been criticized because the test can become easier for individuals to fool with each successive assessment. Brain scanning using fMRI holds much promise as a diagnostic tool in evaluating sexual interests, as research has documented a reliable network of brain regions involved in sexual arousal. The current study took this another step by testing whether brain functional activation could be used to infer what someone finds sexually interesting without them knowing. © 2017 Scientific American,

Keyword: Sexual Behavior; Brain imaging
Link ID: 23783 - Posted: 06.28.2017

By Alice Klein Women are missing out on optimum medical treatment because most pre-clinical drug research is done in male animals, a new study suggests. New drugs must be evaluated in animals before being considered for human trials. Over three-quarters of these studies use only male animals because of concerns that female hormone cycles will affect experiments. It is also widely assumed that what works for males will work for females. However, research by Natasha Karp at the Wellcome Trust Sanger Institute in Cambridge and her colleagues casts doubt on this assumption. They compared 234 physical traits in 14,000 male and female lab mice. Sex differences were identified for 57 per cent of quantifiable traits – like cholesterol level and bone mass – and for 10 per cent of qualitative traits, like head shape. In another 40,000 mice, they found that when they switched off specific genes, the effects varied according to sex. This suggests that genetic diseases may manifest themselves differently in males and females and require different treatments, says Karp. These sex nuances mean that drugs optimised for male animals may be less effective in females, or even cause harm, says Karp. Between 1997 and 2001, 8 of the 10 drugs that were pulled from the market in the US posed greater health risks for women – possibly as a result of male-biased animal research, she says. © Copyright New Scientist Ltd.

Keyword: Sexual Behavior
Link ID: 23780 - Posted: 06.27.2017

By THERESE HUSTON “Does being over 40 make you feel like half the man you used to be?” Ads like that have led to a surge in the number of men seeking to boost their testosterone. The Food and Drug Administration reports that prescriptions for testosterone supplements have risen to 2.3 million from 1.3 million in just four years. There is such a condition as “low-T,” or hypogonadism, which can cause fatigue and diminished sex drive, and it becomes more common as men age. But according to a study published in JAMA Internal Medicine, half of the men taking prescription testosterone don’t have a deficiency. Many are just tired and want a lift. But they may not be doing themselves any favors. It turns out that the supplement isn’t entirely harmless: Neuroscientists are uncovering evidence suggesting that when men take testosterone, they make more impulsive — and often faulty — decisions. Researchers have shown for years that men tend to be more confident about their intelligence and judgments than women, believing that solutions they’ve generated are better than they actually are. This hubris could be tied to testosterone levels, and new research by Gideon Nave, a cognitive neuroscientist at the University of Pennsylvania, along with Amos Nadler at Western University in Ontario, reveals that high testosterone can make it harder to see the flaws in one’s reasoning. How might heightened testosterone lead to overconfidence? One possible explanation lies in the orbitofrontal cortex, a region just behind the eyes that’s essential for self-evaluation, decision making and impulse control. The neuroscientists Pranjal Mehta at the University of Oregon and Jennifer Beer at the University of Texas, Austin, have found that people with higher levels of testosterone have less activity in their orbitofrontal cortex. Studies show that when that part of the brain is less active, people tend to be overconfident in their reasoning abilities. It’s as though the orbitofrontal cortex is your internal editor, speaking up when there’s a potential problem with your work. Boost your testosterone and your editor goes reassuringly (but misleadingly) silent. © 2017 The New York Times Company

Keyword: Hormones & Behavior; Attention
Link ID: 23776 - Posted: 06.26.2017

Cassie Martin Long typecast as the strong silent type, bones are speaking up. In addition to providing structural support, the skeleton is a versatile conversationalist. Bones make hormones that chat with other organs and tissues, including the brain, kidneys and pancreas, experiments in mice have shown. “The bone, which was considered a dead organ, has really become a gland almost,” says Beate Lanske, a bone and mineral researcher at Harvard School of Dental Medicine. “There’s so much going on between bone and brain and all the other organs, it has become one of the most prominent tissues being studied at the moment.” At least four bone hormones moonlight as couriers, recent studies show, and there could be more. Scientists have only just begun to decipher what this messaging means for health. But cataloging and investigating the hormones should offer a more nuanced understanding of how the body regulates sugar, energy and fat, among other things. Of the hormones on the list of bones’ messengers — osteocalcin, sclerostin, fibroblast growth factor 23 and lipocalin 2 — the last is the latest to attract attention. Lipocalin 2, which bones unleash to stem bacterial infections, also works in the brain to control appetite, physiologist Stavroula Kousteni of Columbia University Medical Center and colleagues reported in the March 16 Nature. After mice eat, their bone-forming cells absorb nutrients and release a hormone called lipocalin 2 (LCN2) into the blood. LCN2 travels to the brain, where it gloms on to appetite-regulating nerve cells, which tell the brain to stop eating, a recent study suggests. © Society for Science & the Public 2000 - 2017.

Keyword: Hormones & Behavior
Link ID: 23762 - Posted: 06.22.2017

By Karl Gruber Birds, fish, and even humans have shattered barriers when it comes to mating rituals, from which partner initiates the courting to which one picks up the check at a fancy restaurant. But things are a bit simpler for frogs, as males and females stick to clearly defined roles: Males serenade the females, and females pick their favorite males to mate. Now, a new study suggests that the smooth guardian frog of Borneo (Limnonectes palavanensis) is an exception to that rule. During the mating season, the female frogs sing to the males in an attempt to win them over—a reversal of the normal process. In fact, if you see a single frog surrounded by a bunch of serenading croakers, called a “lek,” it’s most likely a lucky male being courted by a chorus of females. Males occasionally belt out “advertisement calls” to let females know that they are available. After mating, it’s the males who stay behind to care for the eggs, even taking tadpoles to small ponds after they hatch. This is the first known example of role reversal in singing frogs, scientists write in a recent issue of Behavioral Ecology and Sociobiology. It may even represent the first case of full-blown sex role reversal, which would also require that males do the mate choosing. Researchers are working on that now, but they say that—judging by the high rate of female serenading—males may be the picky ones. © 2017 American Association for the Advancement of Science.

Keyword: Sexual Behavior
Link ID: 23755 - Posted: 06.21.2017

Laurel Hamers When things get hot, embryonic bearded dragon lizards turn female — and now scientists might know why. New analyses, reported online June 14 in Science Advances, reveal that temperature-induced changes in RNA’s protein-making instructions might set off this sex switch. The findings might also apply to other reptile species whose sex is influenced by temperature. Unlike most mammals, many species of reptiles and fish don’t have sex chromosomes. Instead, they develop into males at certain temperatures and females at others. Bearded dragon lizards are an unusual case because chromosome combinations and temperature are known to influence sex determination, says ecologist Clare Holleley of the Commonwealth Scientific and Industrial Research Organisation in Canberra, Australia (SN: 7/25/15, p.7). When eggs are incubated below 32° Celsius, embryonic bearded dragons with two Z chromosomes develop as male, while dragons with a Z and a W chromosome develop as female. But as temperatures creep above 32°, chromosomally male ZZ dragons will reverse course and develop as females instead. “They have two sex chromosomes, but they also have this temperature override,” Holleley says. By comparing bearded dragons that are female because of their chromosomes and those that are female because of environmental influences, Holleley and her colleagues hoped to sort out genetic differences that might point to how the lizards make the switch. The team collected RNA from the brain, reproductive organs and other tissues of normal female, normal male and sex-reversed female Australian central bearded dragons (Pogona vitticeps). Then, the researchers compared that RNA, looking for differences in the ways the lizards were turning on genes. |© Society for Science & the Public 2000 - 2017.

Keyword: Sexual Behavior
Link ID: 23745 - Posted: 06.15.2017

By Lenny Bernstein A mother’s fever during pregnancy, especially in the second trimester, is associated with a higher risk that her child will be diagnosed with autism spectrum disorder, researchers reported Tuesday. Three or more fevers after 12 weeks of gestation may be linked to an even greater risk of the condition. The study by researchers at Columbia University’s Mailman School of Public Health adds support for the theory that infectious agents that trigger a pregnant woman’s immune response may disrupt a fetus’s brain development and lead to disorders such as autism. “Fever seems to be the driving force here,” not the infection itself, said Mady Hornig, director of translational research at the school’s Center for Infection and Immunity. Fever can be part of the body’s immune response to an infection, and molecules produced by a mother’s immune system may be crossing into the baby’s neurological system at a critical time, she said. The research, published in the journal Molecular Psychiatry, comes at a time when the scientifically discredited theory that some childhood vaccines cause autism has gained new attention. President Trump has promoted this myth, energizing some anti-vaccine groups. Some families say that their children developed autism after vaccinations. The timing is a coincidence, however; symptoms of autism typically become clear at around two years of age, which happens to be the age when children get certain vaccines. © 1996-2017 The Washington Post

Keyword: Autism
Link ID: 23737 - Posted: 06.13.2017

By RICHARD SANDOMIR Isabelle Rapin, a Swiss-born child neurologist who helped establish autism’s biological underpinnings and advanced the idea that autism was part of a broad spectrum of disorders, died on May 24 in Rhinebeck, N.Y. She was 89. The cause was pneumonia, said her daughter Anne Louise Oaklander, who is also a neurologist. “Calling her one of the founding mothers of autism is very appropriate,” said Dr. Thomas Frazier II, a clinical psychologist and chief science officer of Autism Speaks, an advocacy group for people with autism and their families. “With the gravity she carried, she moved us into a modern understanding of autism.” Dr. Rapin (pronounced RAP-in) taught at the Albert Einstein College of Medicine in the Bronx and over a half-century there built a reputation for rigorous scholarship. She retired in 2012 but continued working at her office and writing journal papers. The neurologist Oliver Sacks, a close friend and colleague, called her his “scientific conscience.” In his autobiography, “On the Move: A Life” (2015), Dr. Sacks wrote: “Isabelle would never permit me, any more than she permitted herself, any loose, exaggerated, uncorroborated statements. ‘Give me the evidence,’ she always says.” Dr. Rapin’s focus on autism evolved from her studies of communications and metabolic disorders that cause mental disabilities and diminish children’s ability to navigate the world. For decades she treated deaf children, whose difficulties in communicating limited their path to excelling in school and forced some into institutions. “Communications disorders were the overarching theme of my mother’s career,” Dr. Oaklander said in an interview. In a short biography written for the Journal of Child Neurology in 2001, Dr. Rapin recalled a critical moment in her work on autism. “After evaluating hundreds of autistic children,” she wrote, “I became convinced that the report by one-third of parents of autistic preschoolers, of a very early language and behavioral regression, is real and deserving of biologic investigation.” © 2017 The New York Times Company

Keyword: Autism
Link ID: 23727 - Posted: 06.12.2017

By Anil Ananthaswamy A machine-learning algorithm has analysed brain scans of 6-month-old children and predicted with near-certainty whether they will show signs of autism when they reach the age of 2. The finding means we may soon be able to intervene before symptoms appear, although whether that would be desirable is a controversial issue. “We have been trying to identify autism as early as possible, most importantly before the actual behavioural symptoms of autism appear,” says team member Robert Emerson of the University of North Carolina at Chapel Hill. Previous work has identified that bundles of nerve fibres in the brain develop differently in infants with older siblings with autism from how they do in infants without this familial risk factor. The changes in these white matter tracts in the brain are visible at 6 months. For the new study, Emerson and his team did fMRI brain scans of 59 sleeping infants, all of whom were aged 6 months and had older siblings with autism, which means they are more likely to develop autism themselves. The scans collected data from 230 brain regions, showing the 26,335 connections between them. When the team followed-up with the children at the age of 2, 11 had been diagnosed with an autism-like condition. The team used the brain scans from when the babies were 6 months old and behavioural data from when the children were 2 years old to train a machine-learning program to identify any brain connectivity patterns that might be linked to later signs of autism, such as repetitive behaviour, difficulties with language, or problems relating socially to others. © Copyright New Scientist Ltd.

Keyword: Autism; Brain imaging
Link ID: 23722 - Posted: 06.08.2017

By LISA SANDERS, M.D. She didn’t have any urgent medical problems, the woman told Dr. Lori Bigi. She was there because she had moved to Pittsburgh and needed a primary-care doctor. Bigi, an internist at the University of Pittsburgh Medical Center, quickly eyed her new patient. She was 31 and petite, just over five feet tall and barely 100 pounds. And she looked just as she described herself, pretty healthy. Doctors often rely on patients’ sense of their well-being, especially when their assessment matches their appearance. But as Dr. Bigi was reminded that day, patients aren’t always right. The patient did say that she had seen her old doctor for awful headaches she got occasionally. They felt like an ice pick through the top of her head, the patient explained, which, at least initially, usually came on while she was going to the bathroom. The headache didn’t last long, but it was intensely painful. Her previous doctor thought it was a type of migraine. He prescribed medication, but it didn’t help. Now her main problem was anxiety, and she saw a psychiatrist for that. Sudden Panic Anxiety is common enough, and because the patient was seeing a specialist, Bigi wasn’t planning to spend much time discussing it. But then the doctor saw that in addition to taking an antidepressant — a recommended treatment for anxiety — the patient was on a sedating medication called clonazepam. It wasn’t a first-line medication for anxiety, and this tiny woman was taking a huge dose of it. The young woman explained that for most of her life, she was not a particularly anxious person. Then, two years earlier, she started experiencing episodes of total panic for seemingly no reason. At the time she chalked it up to a new job — she worked in a research lab — and the pressures associated with a project they had recently started. But the anxiety never let up. © 2017 The New York Times Company

Keyword: Stress; Hormones & Behavior
Link ID: 23721 - Posted: 06.08.2017

Baby teeth from children with autism contain more toxic lead and less of the essential nutrients zinc and manganese, compared to teeth from children without autism, according to an innovative study funded by the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health. The researchers studied twins to control genetic influences and focus on possible environmental contributors to the disease. The findings, published June 1 in the journal Nature Communications, suggest that differences in early-life exposure to metals, or more importantly how a child’s body processes them, may affect the risk of autism. The differences in metal uptake between children with and without autism were especially notable during the months just before and after the children were born. The scientists determined this by using lasers to map the growth rings in baby teeth generated during different developmental periods. The researchers observed higher levels of lead in children with autism throughout development, with the greatest disparity observed during the period following birth. They also observed lower uptake of manganese in children with autism, both before and after birth. The pattern was more complex for zinc. Children with autism had lower zinc levels earlier in the womb, but these levels then increased after birth, compared to children without autism. The researchers note that replication in larger studies is needed to confirm the connection between metal uptake and autism.

Keyword: Autism; Neurotoxins
Link ID: 23698 - Posted: 06.02.2017

Hannah Devlin Science correspondent “Love looks not with the eyes, but with the mind. And therefore is winged Cupid painted blind,” Shakespeare wrote. Now scientists have pinpointed the specific patterns of brain activity that accompany romance, offering a new explanation for why love sends our judgement haywire. As a relationship takes root, the study found, the brain’s reward circuit goes into overdrive, rapidly increasing the value placed on spending time with one’s love interest. This, at least, was the case in the prairie vole, scientists’ animal model of choice for studying the neuroscience of love. Elizabeth Amadei, who co-led the work at Emory University in Atlanta, said: “As humans, we know the feelings we get when we view images of our romantic partners, but, until now, we haven’t known how the brain’s reward system works to lead to those feelings.” In order to get more direct access to what is happening in the brain, Amadei and colleagues turned to the North American voles, which as a species have almost perfected monogamy. They mate for life, share nest-building duties and have an equal role in raising their young – although, like humans, voles have the occasional “extramarital” fling. Using electrical probes, the scientists recorded directly from the brains of female voles as they encountered a potential partner, mated for the first time and began to show signs of having formed a lifelong bond, indicated by “huddling” behaviour.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 23692 - Posted: 06.01.2017

By Ariana Eunjung Cha Depression is usually considered an issue parents have to watch out for starting in the turbulent teenage years. The CW channel, full of characters with existential angst about school, friends and young love, tells us so, as do the countless parenting books about the adolescent years in every guidance counselor's office. But what if by that time it's already too late? A large new study out this week contains some alarming data about the state of children's mental health in the United States, finding that depression in many children appears to start as early as age 11. By the time they hit age 17, the analysis found, 13.6 percent of boys and a staggering 36.1 percent of girls have been or are depressed. These numbers are significantly higher than previous estimates. Understanding the risk of depression is critically important because of the close link between depressive episodes and serious issues with school, relationships and suicide. While researchers have long known about the gender gap in depression, with more adult women than men suffering from the condition, the new numbers show that whatever divergent paths boys and girls take happens even earlier than expected. Published in the journal Translational Psychiatry, the study was based on data compiled from in-person interviews with more than 100,000 children who participated in the National Survey of Drug Use and Health from 2009 to 2014. The NSDUH is an annual survey on a representative sample of the U.S. population. Among the standard questions asked are ones about insomnia, irritability, and feelings of guilt or worthlessness that researchers used to “diagnose” survey participants with depression using diagnostic criteria from the Diagnostic and Statistical Manual of Mental Disorders. Through the survey, they were able to capture a broader group of children than those who have a formal diagnosis and who may be in treatment. © 1996-2017 The Washington Post

Keyword: Depression; Development of the Brain
Link ID: 23687 - Posted: 06.01.2017

By STEPH YIN A female and male get together. One thing leads to another, and they have sex. His sperm fuses with her egg, half of his DNA combining with half of her DNA to form an embryo. As humans, this is how we tend to think of reproduction. But there are many other bizarre ways reproduction can take place. For instance, scientists have discovered a fish carrying genes only from its father in the nucleus of its cells. Found in a type of fish called Squalius alburnoides, which normally inhabits rivers in Portugal or Spain, this is the first documented instance in vertebrates of a father producing a near clone of itself through sexual reproduction — a rare phenomenon called androgenesis — the researchers reported in the journal Royal Society Open Science on Wednesday. The possibility of androgenesis is just one of many mysteries about Squalius alburnoides. It’s not a species in the usual sense, but rather something called a hybrid complex, a group of organisms with multiple parental combinations that can mate with one another. The group is thought to have arisen from hybridization between females of one species, Squalius pyrenaicus, and males of another species, now extinct, that belonged to a group of fish called Anaecypris. To sustain its population, Squalius alburnoides mates with several other closely related species belonging to the Squalius lineage. That it can reproduce at all is unusual enough. Most hybrids, like mules, are sterile because the chromosomes from their parents of different species have trouble combining, swapping DNA and dividing — steps required for egg or sperm production. Squalius alburnoides males circumvent this problem by producing sperm cells that do not divide, and therefore contain more than one chromosome set. This is important because most animals, Squalius alburnoides included, need at least two chromosome sets to survive. © 2017 The New York Times Company

Keyword: Sexual Behavior; Evolution
Link ID: 23669 - Posted: 05.27.2017

Tonight, our economics correspondent, Paul Solman, explores another potential connection: whether there’s a link between risk-taking in leadership, testosterone and the perceptions around gender. It’s part of his ongoing weekly series, Making Sense, which airs every Thursday. MAN: Welcome, everybody, to this CNBC discussion on the future of banking at the World Economic Forum. PAUL SOLMAN: Financial CEOs at Davos this year. ANDREW LIVERIS, CEO, Dow Chemical: Good morning. Mr. President. Andrew Liveris, Dow Chemical. PAUL SOLMAN: Manufacturing CEOs at the White House. MARK FIELDS, CEO, Ford Motor Company: CEO of Ford. DOUGLAS OBERHELMAN, CEO, Caterpillar: Chairman of Caterpillar. PRESIDENT DONALD TRUMP: Some of the great people in the world of business. PAUL SOLMAN: CEOs now being mentioned as the next president. But, in 2017, the vast majority of CEOs, 96 percent of the Fortune 500, are still men. JENNIFER LERNER, Harvard University: I think that this is socially constructed. The differences between males and females on a wide variety of things are smaller than the differences within males and within females. PAUL SOLMAN: Psychologist Jennifer Lerner studies gender and leadership at Harvard. We will hear more from her in a bit. But, first, let’s check in with economist Andy Kim, who has made a career out of studying CEOs in intriguingly quirky ways. Now, a few of you might remember Andy Kim teaching me two years ago the equestrian dance move in the hyper-viral video sensation “Gangnam Style,” part of his offbeat research showing that CEOs who become visible, for whatever reason, can see their stock price rise irrationally. Well, he presented his brand-new research, not yet published, at this year’s annual Economics Convention. His latest hypothesis is as offbeat as ever. ANDY KIM: There is a strong linkage between your facial masculinity and your risk-taking behavior. PAUL SOLMAN: Kim is now exploring a possible link between CEO risk-taking and the hormone testosterone, which, starting with mid-19th century experiments on roosters, has been linked to male dominance and aggression throughout the animal kingdom. But how do you measure testosterone in CEOs with little time and probably even less inclination to give Korean assistant finance professors blood or saliva samples? One possible way, thought Kim, would be to study their facial bone structure. © 1996 - 2017 NewsHour Productions LLC.

Keyword: Sexual Behavior; Aggression
Link ID: 23663 - Posted: 05.26.2017

James Gorman Darwin’s finches, those little birds in the Galápagos with beaks of different sizes and shapes, were instrumental in the development of the theory of evolution. Similar birds had large and small beaks and beaks in between, all related to what kinds of insects and seeds they ate. From one ancestor, it seemed, different adaptations to the environment had evolved, giving the birds that adapted a survival edge in a particular ecological niche — evolution by natural selection. Biologists who came later went on to identify the genetic changes that had produced different beak shapes. Now another group of finch-like birds has provided a similar example, but of a different kind of evolution, one driven not by the demands of the environment, but by the demands of female birds. Their preferences in color and pattern caused the evolution of different species of seedeater, all with the same behavior and diet, but with males that look different. That’s a process called sexual selection, which Darwin also wrote about. Leonardo Campagna, a researcher at Cornell University and the Cornell Lab of Ornithology, and a group of scientists from the United States and South America investigated nine species of southern capuchino seedeaters, doing full genomes for each one and reported their findings in Science Advances. They found that the DNA of all the species is remarkably similar, as are the birds. All the females look alike and all of the species feed on grass seeds plucked from grass stalks of living plants. Only the males are different. They have a wide variety of colorations and their courting songs are also distinct. Dr. Campagna and the other researchers found that differences between species DNA were all minimal, ranging from as little as 0.03 percent to as great as 0.3 percent. All the species showed variation in the same area, DNA that appeared to have a role in regulating genes for the pigment melanin. © 2017 The New York Times Company

Keyword: Evolution; Sexual Behavior
Link ID: 23660 - Posted: 05.25.2017

Elle Hunt About 150 years ago, and “almost a lifetime” either side, Charles Darwin was beleaguered by the problem of the peacock’s tail. Just the sight of a feather, he wrote in April 1860, “makes me sick!” The plumage of the male bird represented a hole in his theory of evolution. According to Victorian thinking, beauty was divine creation: God had designed the peacock for his own and humankind’s delight. In, On The Origin of Species, published the previous year, Darwin had challenged the dominant theory of creationism, arguing that man had been made not in God’s image but as a result of evolution, with new species formed over generations in response to their environment. But beauty, and a supposed aesthetic sense in animals (“We must suppose [that peahens] admire [the] peacock’s tail, as much as we do,” he wrote), took Darwin the best part of his life to justify – not least because the theory he eventually landed upon went against the grain of his entire worldview. Sexual selection was of strategic importance to Darwin, says Evelleen Richards, an honorary professor in history and philosophy of science at the University of Sydney: it was a naturalistic account for aesthetic differences between male and female animals of the same species, shoring up his defence of natural selection.

Keyword: Evolution; Sexual Behavior
Link ID: 23642 - Posted: 05.22.2017

Susan Milius The supermoms of the mammal world are big, shy redheads. Studying growth layers in orangutan teeth shows that mothers can nurse their youngsters for eight-plus years, a record for wild mammals. Teeth from a museum specimen of a young Bornean orangutan (Pongo pygmaeus) don’t show signs of weaning until 8.1 years of age. And a Sumatran orangutan (P. abelii) was still nursing during the few months before it was killed at 8.8 years, researchers report May 17 in Science Advances. Tests also show that youngsters periodically start to taper off their dependence on their mother’s milk and then, perhaps if solid food grows scarce, go back to what looks like an all-mom diet. Such on-again, off-again nursing cycles aren’t known in other wild mammals, says study coauthor Tanya Smith, an evolutionary anthropologist at Griffith University in Nathan, Australia. Marks of milk drinking Two images of a cross section of a first molar from a 4.5-year-old Bornean orangutan are shown. At left, numbers indicate days from birth (dotted line, starting with 0) when particular spots formed. At right, colors indicate concentrations of barium, which increase (shading toward red) when the youngster depended more on mother’s milk. A greenish swath at the top indicates nursing as an infant that gave way to blue as solid food became part of the diet. Yellow and red streaks indicate repeated times when the youngster again depended mostly on milk for nutrition. oragutan molar |© Society for Science & the Public 2000 - 2017.

Keyword: Sexual Behavior; Development of the Brain
Link ID: 23632 - Posted: 05.18.2017

Nicola Davis Humans can determine a dog’s mood by the sound of its growl, scientists have found, with women showing greater ability than men. While previous studies have found that humans can unpick the context of barks, the latest study investigated whether the same was true of canine grumbles, with some previous research suggesting humans struggle to differentiate between playful and aggressive vocalisations. “It is an important thing that humans are capable [of recognising] the emotional state of another species just based on the vocal characteristics,” said Tamás Faragó, first author of the study from Eötvös Loránd University in Hungary. To tackle the conundrum, Faragó and colleagues used previously captured recordings of 18 dogs growling in three contexts: guarding food from other dogs, playing tug-of-war with humans, and being threatened by the approach of a stranger. The researchers monitored several features, including the length of each growl and its frequency. Two sets of the recordings, which included two growls from each context, were played to 40 adults. Each participant was asked to record their impression of the first set of growls on a sliding scale, rating their perception of the dog for five emotions: fear, aggression, despair, happiness and playfulness. © 2017 Guardian News and Media Limited

Keyword: Animal Communication; Sexual Behavior
Link ID: 23621 - Posted: 05.17.2017

By Hannah Furfaro, Children whose fathers are highly intelligent are at a 31 percent higher risk of autism than those whose fathers are of average intelligence, according to unpublished results presented today at the 2017 International Meeting for Autism Research in San Francisco, California. The work supports observations that date back to the 1940s, when Leo Kanner and Hans Asperger noted in separate reports that the fathers of children with autism tended to be highly intelligent and in several cases worked in technical fields. A 2012 study also showed that children from regions in the Netherlands where high-tech jobs are prevalent are more likely to have autism than those who live in other regions. In the new study, lead investigator Renee Gardner, assistant professor at Karolinska Institutet in Stockholm, set out to investigate whether the historical lore has validity. She and her colleagues matched medical records for 309,803 children whose fathers were conscripted into the Swedish military with their father’s scores on the technical portion of the Swedish intelligence quotient (IQ) test. They found a one-third higher risk of autism in children whose fathers’ IQ scores are 111 or higher than in those whose fathers’ scores cluster around 100. The researchers controlled for possible confounding factors such as families’ socioeconomic status and parental age, education level and history of inpatient psychiatric treatment. IQ indicators: They found the opposite relationship between a father’s IQ and his child’s chances of having intellectual disability or attention deficit hyperactivity disorder (ADHD). In particular, children of men with an IQ of 75 or below had a four-and-a-half times higher risk of intellectual disability. The chance of ADHD was 65 percent higher than average for children whose fathers had an IQ in that low range. © 2017 Scientific American

Keyword: Autism; Intelligence
Link ID: 23614 - Posted: 05.15.2017