Links for Keyword: Sexual Behavior

Follow us on Facebook and Twitter, or subscribe to our mailing list, to receive news updates. Learn more.


Links 1 - 20 of 1291

by Lisa Grossman Marriage for all, no gay gene required. For same-sex couples in the US, 26 June was a landmark date: the Supreme Court legalised marriage between two men or two women in all 50 states. "[Same-sex couples] ask for equal dignity in the eyes of the law," wrote Associate Justice Anthony Kennedy in the decision. "The Constitution grants them that right." But one thing the decision didn't do was declare sexual orientation a "suspect class" under the law, which would have given it the same protection as race. One of the criteria for this classification is that the trait must be immutable – an argument that the gay rights movement has internalised under the banner of "we're born this way". But although there is some evidence that sexual orientation has a genetic component, most scientists agree that it's not that simple. "There's significant consensus in the scientific community that there's enough different interacting causes for sexual orientation that two different individuals can be gay for different combinations of reasons," says sexuality researcher Lisa Diamond at the University of Utah. "I think all the evidence suggests that we're born with an underlying capacity and then that capacity interacts with a whole bunch of other influences," she says – whether they be prenatal, genetic or environmental. © Copyright Reed Business Information Ltd

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 21117 - Posted: 07.01.2015

by Colin Barras Men often lose their sex drive with age – and so, it seems do male Drosophila. Tsai-Feng Fu at the National Chi Nan University in Taiwan and his colleagues suspected that low levels of dopamine in the flies were to blame. Almost 300 neurones in the fruit-fly brain use dopamine. Comparing those linked to sexual function in elderly 40-day-old male flies and sprightly 10-day-old flies, Fu found the older neurones carried 10 times less dopamine. Boosting levels lengthened the time the older flies spent trying to mate. There are obviously big differences between a man's brain and that of a male Drosophila, but Fu says that the new results could provide a useful starting point for in-depth studies that may have clinical implications. For instance, that research might eventually identify ways to fine-tune dopamine levels in humans, perhaps to reverse age-related declines in sexual drive, or even to suppress an overactive libido. We already have therapies for treating male sexual dysfunction – notably the drug viagra. But probing the link between dopamine and sexual dysfunction is still important. For instance, dopamine-replacement therapy is one of the most effective treatments for Parkinson's disease – but the therapy can lead to harmful compulsive sexual behaviour. But Wendi Neckameyer at the Saint Louis University School of Medicine in Missouri isn't sure we should talk about potential implications for men just yet – it's enough to say that the researchers "have begun to tease out an incredibly complex neural circuit", she says. © Copyright Reed Business Information Ltd

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 21115 - Posted: 07.01.2015

by Curtis Abraham A step forward for equal LGBT rights in Africa. Last week, the influential Academy of Science of South Africa (ASSAf) published a study on the science of human sexual diversity. A comprehensive review of recent scientific papers on the subject, it concluded that sexual behaviour is naturally varied, and discrimination unjustified. It stated that there is no evidence that orientation can be altered by therapy or that being gay is contagious. The report also sets straight the idea that homosexuality is a Western malaise: "There is no basis for the view that homosexuality is 'un-African' either in the sense of it being a 'colonial import', or on the basis that prevalence of people with same-sex or bisexual orientations is any different in African countries compared to countries on any other continent." Going further, the report asserted not only that tolerance of sexual diversity benefits communities but it positively affects public health, civil society and long-term economic growth. Zero tolerance Launched at the Seventh South African AIDS Conference in Durban, the study comes a year after the Ugandan government passed a law imposing a life sentence on anyone who has sexual relations with someone of the same sex. Other countries, including Burundi, Cameroon and Nigeria, then passed similar anti-gay laws. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 21071 - Posted: 06.18.2015

Tom Bawden The mystery behind the nightingale’s beautiful song has been revealed, with scientists finding that male birds sing complex notes to prove to females that they would be a good father to their children. Nightingales use their songs to advertise their family values, according to new research which discovers that the better the singer, the more support they are likely to offer their young family by feeding and defending them from predators. But while the beauty comes from the complexity of the song, the effect it has on the females is based on something far more mundane – the amount of effort the singer has put into his performance. Researchers at the Freie Universitat Berlin found that complicated choral arrangements are much harder to sing, especially when they include frequent appearances of long buzzing sounds and require the bird to be in good physical condition. “We don’t think the female is concerned with the beauty of the song but rather the information encoded in the song that tells her about the singer’s characteristics – his age, where he was raised, the strength of his immune system and how motivated he is to contribute to bringing up the young,” Professor Silke Kipper, one of the report’s authors, told The Independent. “The songs can also be a good indication of the bird’s ability to learn, which is another important characteristic of a good parent.” © independent.co.uk

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 15: Language and Our Divided Brain
Link ID: 21067 - Posted: 06.18.2015

by Michael Sean Pepper and Beverley Kramer People who are attracted to others of the same sex develop their orientation before they are born. This is not a choice. And scientific evidence shows their parents cannot be blamed. Research proving that there is biological evidence for sexual orientation has been available since the 1980s. The links have been emphasised by new scientific research. In 2014, researchers confirmed the association between same-sex orientation in men and a specific chromosomal region. This is similar to findings originally published in the 1990s, which, at that time, gave rise to the idea that a “gay gene” must exist. But this argument has never been substantiated, despite the fact that studies have shown that homosexuality is a heritable trait. Evidence points towards the existence of a complex interaction between genes and environment, which are responsible for the heritable nature of sexual orientation. These findings are part of a report released by the Academy of Science South Africa. The report is the outcome of work conducted by a panel put together in 2014 to evaluate all research on the subject of sexual orientation done over the last 50 years. It did this against the backdrop of a growing number of new laws in Africa which discriminate against people attracted to others of the same sex. The work was conducted in conjunction with the Ugandan Academy of Science.

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 21049 - Posted: 06.15.2015

by Clare Wilson The first drug for treating low sexual desire in women looks set to go on sale in the US next year Flibanserin, sometimes called the female Viagra, was approved by 18 votes to 6 by a US Food and Drug Administration advisory panel yesterday, although some of the committee members had doubts about the drug's risks and benefits. They required that certain "risk-management options" be put in place, on top of the usual list of side effects listed in the medicine's patient information leaflet. We have yet to hear what this means, but options include doctors having to verbally warn women not to drink alcohol or use various other medicines when taking the drug. The FDA's final say is due by August, but it usually follows the decision of its advisory panel. Assuming it gets the go-ahead, manufacturer Sprout Pharmaceuticals of Raleigh, North Carolina, plans to give the drug the brand-name Addyi, and has promised not to advertise the product directly to patients – which is normally allowed in the US – for the first 18 months it goes on sale. Addyi is no Viagra though – women would have to take it every day, whether or not they want sex. And, while the famous little blue pill works by increasing blood flow to the genitals, this new drug instead alters brain chemistry, affecting receptors for various signalling chemicals including serotonin and dopamine. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 21020 - Posted: 06.06.2015

By Elahe Izadi Researchers classified two new species of Dusky Antechinus, mouse-like creatures that engage in suicidal reproduction, and published their findings last week in the peer-reviewed journal Memoirs of the Queensland Museum -- Nature. The Mainland Dusky Antechinus, found in southeastern Australia, has been elevated from sub-species to a distinct species. And the newly discovered Tasman Peninsula Dusky Antechinus, found in southeastern Tasmania, already faces the threat of extinction due in part to loss of habitat and feral pests, researchers said. Their proclivity for ferocious, suicidal sex frenzies aren't helping them any. "The breeding period is basically two to three weeks of speed-mating, with testosterone-fueled males coupling with as many females as possible, for up to 14 hours at a time," lead author Andrew Baker of the Queensland University of Technology said in a release. All of that testosterone "triggers a malfunction in the stress hormone shut-off switch" for the males, Baker said. The males then get so stressed out that their immune systems fail, and they die before the females actually give birth. Suicidal reproduction -- or semelparity-- is rare in mammals, and has so far just been documented in these kinds of marsupials.

Related chapters from BP7e: Chapter 6: Evolution of the Brain and Behavior; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 21015 - Posted: 06.03.2015

Allie Wilkinson For many species, reproduction is a duet between male and female. Now, for the first time, scientists report evidence of 'virgin birth' in a wild vertebrate, the smalltooth sawfish. The fish (Pristis pectinata) normally reproduces sexually, requiring contributions from both sexes. But the latest analysis estimates that nearly 4% of sawfish in a Florida estuary were born without any genetic contribution from a male, in a phenomenon known as parthenogenesis. This asexual reproduction is rare in vertebrates, and had previously been observed only in a handful of species in captivity, including snakes collected from the wild1 and Komodo dragons2. The latest findings appear in the 1 June issue of Current Biology3. Smalltooth sawfish are one of five large ray species that have chainsaw-like appendages protruding from their faces, and are in the same subclass as sharks. The smalltooth sawfish was once abundant along the US eastern and southern coastlines from North Carolina to Texas, but overfishing and coastal development have drastically reduced its numbers. The critically endangered fish are now found only off the coast of southwest Florida. Researchers discovered evidence of 'virgin births' among the sawfish while conducting a routine genetic analysis to determine whether they were inbreeding. Some of the 190 sawfish sampled in a Florida estuary showed unusually high levels of relatedness to other fish in the same population. © 2015 Nature Publishing Group

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 21009 - Posted: 06.02.2015

By ANDREW POLLACK Is sexual desire a human right? And are women entitled to a little pink pill to help them feel it? Those questions are being raised in a campaign that is pressing the Food and Drug Administration to approve a pill aimed at restoring lost libido in women. The campaign, backed by the drug’s developer and some women’s groups, accuses the F.D.A. of gender bias for approving Viagra and 25 other drugs to help men have sex, but none for women. “Women have waited long enough,” the effort, known as Even the Score, says in an online petition that has gathered more than 40,000 signatures. “In 2015, gender equality should be the standard when it comes to access to treatments for sexual dysfunction.” The drug, flibanserin, has been rejected twice by the F.D.A. on the grounds that its very modest effectiveness was outweighed by side effects like sleepiness, dizziness and nausea. The first rejection, in 2010, followed a decision by a committee of outside advisers to the agency who unanimously opposed approval. On Thursday, F.D.A. advisers will once again consider whether flibanserin should be approved. Sprout Pharmaceuticals, which now owns the drug, has submitted new data, including a study to demonstrate that the pill does not impair driving. Still, approval might hinge on whether the F.D.A. agrees to interpret the old data in a new way and whether the politics of such drugs has changed. © 2015 The New York Times Company

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 21002 - Posted: 06.01.2015

By Sarah C. P. Williams Here’s an easy way to tell if a female warbler is a year-round resident of the tropics or just a visiting snowbird: Females from species that spend their lives near the equator tend to have brighter plumage more typical of male birds. In contrast, females who fly north for the summer appear drab compared with their male counterparts. In the past, researchers thought the difference was due to the shorter breeding season in the north, hypothesizing that migrating males evolved bright colors to better compete for mates. But a new study hints that northern-breeding females may have evolved to be less colorful than males in order to be less conspicuous to predators during their long migrations. Researchers at Trinity University in San Antonio, Texas, studied the coloring, migration patterns, breeding locales, and ancestry of 109 warbler species. Migration distance, not the length of the breeding season, was the best predictor of color contrasts between male and female birds, they report online today in the Proceedings of the Royal Society B. Female bay-breasted warblers (Setophaga castanea), for instance, which migrate about 7000 kilometers between their breeding grounds in North America and their wintering grounds in the Caribbean, are a dull gray and white, whereas males boast more showy yellows and browns. But both male and female slate-throated redstarts (Myioborus miniatus), like the one shown above, flaunt bright colors in their year-round tropical homes in Mexico and Central America. For migrating warblers, the researchers hypothesize that the breeding benefits of brighter male colors outweigh the threat of being spotted by a hungry predator. © 2015 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 20984 - Posted: 05.27.2015

By BENEDICT CAREY and PAM BELLUCK He was a graduate student who seemingly had it all: drive, a big idea and the financial backing to pay for a sprawling study to test it. In 2012, as same-sex marriage advocates were working to build support in California, Michael LaCour, a political science researcher at the University of California, Los Angeles, asked a critical question: Can canvassers with a personal stake in an issue — in this case, gay men and women — actually sway voters’ opinions in a lasting way? He would need an influential partner to help frame, interpret and place into context his findings — to produce an authoritative scientific answer. And he went to one of the giants in the field, Donald P. Green, a Columbia University professor and co-author of a widely used text on field experiments. “I thought it was a very ambitious idea, so ambitious that it might not be suitable for a graduate student,” said Dr. Green, who signed on as a co-author of Mr. LaCour’s study in 2013. “But it’s such an important question, and he was very passionate about it.” Last week, their finding that gay canvassers were in fact powerfully persuasive with people who had voted against same-sex marriage — published in December in Science, one of the world’s leading scientific journals — collapsed amid accusations that Mr. LaCour had misrepresented his study methods and lacked the evidence to back up his findings. On Tuesday, Dr. Green asked the journal to retract the study because of Mr. LaCour’s failure to produce his original data. Mr. LaCour declined to be interviewed, but has said in statements that he stands by the findings. © 2015 The New York Times Company

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 20979 - Posted: 05.26.2015

Richard A. Friedman AMERICANS disapprove of marital infidelity. Ninety-one percent of them find it morally wrong, more than the number that reject polygamy, human cloning or suicide, according to a 2013 Gallup poll. Yet the number of Americans who actually cheat on their partners is rather substantial: Over the past two decades, the rate of infidelity among married men has been pretty constant at around 21 percent, while the percentage of married women who admitted to cheating has mostly hovered between 10 and 15 percent, according to the General Social Survey at the University of Chicago’s independent research organization, NORC. We are accustomed to thinking of sexual infidelity as a symptom of an unhappy relationship, a moral flaw or a sign of deteriorating social values. When I was trained as a psychiatrist we were told to look for various emotional and developmental factors — like a history of unstable relationships or a philandering parent — to explain infidelity. But during my career, many of the questions we asked patients were found to be insufficient because for so much behavior, it turns out that genes, gene expression and hormones matter a lot. Now that even appears to be the case for infidelity. We have long known that men have a genetic, evolutionary impulse to cheat, because that increases the odds of having more of their offspring in the world. But now there is intriguing new research showing that some women, too, are biologically inclined to wander, although not for clear evolutionary benefits. Women who carry certain variants of the vasopressin receptor gene are much more likely to engage in “extra pair bonding,” the scientific euphemism for sexual infidelity. © 2015 The New York Times Company

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 8: Hormones and Sex
Link ID: 20970 - Posted: 05.23.2015

By SINDYA N. BHANOO Male Java sparrows are songbirds — and, scientists reported on Wednesday, natural percussionists. The sparrows click their bills against a hard surface while singing. That clicking is done in coordination with the song, much as a percussion instrument accompanies a melody. Researchers at Hokkaido University in Japan observed the birds producing clicks frequently toward the beginning of their songs and around specific notes. Birds that were related produced similar percussive patterns, but whether this behavior is learned or innate is unclear. Next the scientists, who described their findings on Wednesday in the journal PLOS One, would like to know whether male sparrows use bill clicks during courtship communication. © 2015 The New York Times Company

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 20963 - Posted: 05.21.2015

Margaret Wente Child psychiatrist Susan Bradley was a pioneer in treating kids with gender-identity disorders. In the 1970s, she founded the child and adolescent gender identity clinic at the Clarke Institute in Toronto, which eventually became part of the Centre for Addiction and Mental Health (CAMH). Back then, the field was virtually unknown. Today, it is Ground Zero in a fierce battle between oldfangled psychiatry and transgender activists who insist that practitioners like Dr. Bradley are guilty of child abuse. Caught in the middle are confused parents, well-meaning schools, and – most important of all – troubled and bewildered kids. The new rush to turn little Jason into Janey, or Sally into Sam, is generally regarded (in the media, at least) as progress – proof of what a tolerant and progressive society we’ve become. But what if it’s just another fad? What if the radical step of changing genders isn’t always the right answer for a child’s emotional distress – especially when that child is only 10 or 6, or 3? “Some of these kids are quite significantly ill,” says Dr. Bradley. “They often have serious family problems and anxiety disorders. Or they’ve had serious trauma. A girl I saw had been raped, and after that she decided she was going to be a male. If you didn’t pay attention to the trauma you’re not doing that kid a service.” These days, that eminently reasonable view is being challenged by people who believe that children’s sexual confusion should automatically be taken at face value. The clinic that Dr. Bradley helped to found – which does, in fact, support gender transition for a sizable minority of its patients – is being pilloried as transphobic. “Is CAMH trying to turn trans kids straight?” screamed a headline in NOW magazine. Under pressure from activists, CAMH has put its gender clinic under six-month review. And a new bill before the Ontario legislature, which is supported by Premier Kathleen Wynne, would explicitly bar the therapeutic approach taken by the clinic, wrongly equating it to the notorious “conversion” therapy that seeks to turn gay people straight. © Copyright 2015 The Globe and Mail Inc.

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 13: Memory, Learning, and Development
Link ID: 20907 - Posted: 05.11.2015

|By Brian Bienkowski and Environmental Health News Male minnows exposed to a widely used diabetes drug ubiquitous in wastewater effluent had feminized reproductive parts and were smaller and less fertile, according to a new study. It is the first study to examine the drug metformin’s impact on fish endocrine systems and suggests that non-hormone pharmaceuticals pervasive in wastewater may cause reproductive and development problems in exposed fish. Metformin is largely used to combat insulin resistance associated with type-2 diabetes, which accounts for about 90 percent of all diagnosed U.S. adult diabetes cases. Researchers from the University of Wisconsin-Milwaukee exposed young fathead minnows to water containing levels of metformin commonly found in wastewater effluent. Eighty-four percent of 31 metformin-exposed male fish exhibited feminized reproductive organs. “Normally in females you see eggs developed in ova, in males, you see a different structure – producing tiny sperm instead of an egg structure,” said Rebecca Klaper, an associate professor at the University of Wisconsin-Milwaukee and senior author of the study. “We saw development of larger egg structures within the [male’s] testis.” © 2015 Scientific American

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 20867 - Posted: 04.30.2015

Boer Deng Universities in the United States employ many more male scientists than female ones. Men are paid more, and in fields such as mathematics, engineering and economics, they hold the majority of top-level jobs. But in a sign of progress, a 13 April study finds that faculty members prefer female candidates for tenure-track jobs in science and engineering — by a ratio of two to one. That result, based on experiments involving hypothetical job seekers, held true regardless of the hirer’s gender, department, career status or university type, researchers report in the Proceedings of the National Academy of Sciences1. “We were shocked,” says Wendy Williams, a psychologist at Cornell University in Ithaca, New York, and a co-author of the study. With fellow Cornell psychologist Stephen Ceci, she surveyed 873 tenure-track faculty members in biology, psychology, economics and engineering at 371 US universities. One experiment presented participants with three hypothetical job candidates, of which two were identical except for their gender. Another experiment added descriptions of marital and parental status, to test whether underlying assumptions about gender choices affected hiring. “You don’t frequently see that level of attention and sophistication” in statistical analysis, says Robert Santos, vice-president of the American Statistical Association in Alexandria, Virginia. Nothing seemed to sway study participants’ preference for female job candidates. The authors say that this is interesting given their previous finding that a relatively low percentage of female PhDs in the social and biological sciences secure academic positions — in part because they are less likely than men to apply for these jobs. Other research suggests that in the physical sciences, women and men are just as likely to secure a tenure-track position within five years of earning a PhD. © 2015 Nature Publishing Group

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 20792 - Posted: 04.14.2015

by Bethany Brookshire In 2011, a group of scientists “turned mice gay.” The only issue is, of course, they didn’t. Rather, Yi Rao and colleagues at Peking University in Beijing, China, showed that male mice will cheerfully mount both male and female mice, as long as their brains are deficient in one chemical messenger: serotonin. The paper, published in Nature, received plenty of media coverage. Now, two other research groups report seemingly opposite findings: Male mice with no serotonin in their brains still prefer female mice to males. The researchers contend that serotonin is about social communication and impulsive behaviors, not sex. Mounting behavior aside, sexual preference in mice is not about “turning mice gay.” It never has been. Instead, it’s about the role that a single chemical can play in animal behavior. And it’s about what, exactly, those behaviors really mean. Serotonin serves as a messenger between cells. It plays important roles in mood. Serotonin-related drugs are used to treat some forms of migraine. And of course, serotonin plays a role in the psychedelic effects of recreational drugs such as hallucinogens. So when the Peking University group set out to show serotonin’s role in sexual preference, they attacked it from several angles. They used mice that had been genetically engineered to lack the brain cells that usually produce serotonin. They used a chemical to deplete serotonin in the brains of normal mice. And they created another strain of mice that lacked the enzyme that makes serotonin in the brain. © Society for Science & the Public 2000 - 2015

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 20787 - Posted: 04.11.2015

Drawing on the widest survey of sexual behaviour since the Kinsey Report, David Spiegelhalter, in his book Sex By Numbers, answers key questions about our private lives. Here he reveals how Kinsey’s contested claim that 10% of us are gay is actually close to the mark For a single statistic to be the primary propaganda weapon for a radical political movement is unusual. Back in 1977, the US National Gay Task Force (NGTF) was invited into the White House to meet President Jimmy Carter’s representatives – a first for gay and lesbian groups. The NGTF’s most prominent campaigning slogan was “we are everywhere”, backed up by the memorable statistical claim that one in 10 of the US population was gay – this figure was deeply and passionately contested. So where did Bruce Voeller, a scientist who was a founder and first director of the NGTF, get this nice round 10% from? To find out, we have to delve back into Alfred Kinsey’s surveys in 1940s America, which were groundbreaking at the time but are now seen as archaic in their methods: he sought out respondents in prisons and the gay underworld, made friends with them and, over a cigarette, noted down their behaviours using an obscure code. Kinsey did not believe that sexual identity was fixed and simply categorised, and perhaps his most lasting contribution was his scale, still used today, in which individuals are rated from exclusively heterosexual to exclusively homosexual on a scale of 0 to 6. Kinsey’s headline finding was that “at least 37% of the male population has some homosexual experience between the beginning of adolescence and old age”, meaning physical contact to the point of orgasm. © 2015 Guardian News and Media Limited

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 20760 - Posted: 04.06.2015

by Alison George Misguided notions about our sexual appetites are missing the bigger picture and making people unhappy, says Emily Nagoski Why is there no such thing as a sex drive? A drive is a motivational system to deal with life-or-death issues, like hunger or being too cold. You're not going to die if you don't have sex. But biologists might say that if you don't reproduce, that is a form of death Yes. That's the argument that was used when desire was being added to the way sexual dysfunctions were diagnosed in the 1970s, to justify the framing of sexual desire as a drive. But when it comes to sex, there just isn't any physical evidence of a drive mechanism. So what's going on? If sex is a drive then desire should be spontaneous, like a hunger. When you see a sexy person or have a stray sexy thought, it activates an internal craving or urge for sex. That's called "spontaneous desire". It feels like it comes out of the blue. But there is another way of experiencing desire which is also healthy and normal, called "responsive desire", where your interest only emerges in response to arousal. So, your partner comes over and starts kissing your neck and you're like, "oh, right, sex, that's a good idea". Do you think an absence of spontaneous desire is normal? Yes. If our metaphor for desire is hunger, if you are never hungry for food there will be dire consequences and that's clearly a disorder, right? That's a medical problem that needs to be fixed. But not experiencing spontaneous hunger for sex doesn't have dire consequences; it is not a medical disorder. I think the reason we expect everyone to have spontaneous desire is because that's how most men experience it. © Copyright Reed Business Information Ltd

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 20759 - Posted: 04.06.2015

By Anna Azvolinsky Differences in male and female rodent sexual behaviors are programmed during brain development, but how exactly this occurs is not clear. In the preoptic area (POA) of the brain—a region necessary for male sex behavior—the female phenotype results from repression of male-linked genes by DNA methylation, according to a study published today (March 30) in Nature Neuroscience. There is very little known about how the brain is masculinized—and even less about how it is feminized—even though the question has been studied for more than 50 years, said Bridget Nugent, study author and now a postdoctoral fellow at the University of Pennsylvania. These sex differences in the brain are programmed toward the end of fetal development, through to one week after birth in rodents. In males, testicular hormones drive masculinization of the brain; this was thought to occur by direct induction of gene expression by hormone-associated transcription factors. Because a feminized brain occurred in the absence of ovarian hormone signals, most researchers assumed that the female brain and behavior was a sort of default state, programmed during development when no male hormones are present. But the downstream mechanisms of how hormones can modify gene expression were not previously known. “This study reveals that DNA methylation plays an important role in regulating sexual differentiation,” said Nirao Shah, who also studies the neural basis for sex-specific behaviors at the University of California, San Francisco, but was not involved with the work. © 1986-2015 The Scientist

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 20740 - Posted: 03.31.2015