Studying the intimate relationship between narcissism and satisfaction
by Elaine Smith
[I]f you learned that your next-door neighbours were having sexual relations more frequently than you and your partner, would it bother you?
Three U of T Mississauga researchers set out to understand how people view their sex lives in comparison to those of others and discovered that sexual narcissism colours the way people make and view those comparisons.
“For some people, those comparisons are pretty influential,” said Lisa Day, a PhD candidate at UTM.
In new research published in the Personality and Social Psychology Bulletin, Day, Emily Impett, a UTM psychology professor, and Amy Muise (now a York University professor) looked at how these comparisons affect both relationship satisfaction and sexual satisfaction for people with varying degrees of sexual narcissism.
Sexual narcissism should not be confused with general narcissistic personality traits. It is defined as “the tendency to exploit others, a lack of empathy, feelings of grandiosity and an excessive need for validation in the sexual domain.” They’re the people, for example, who buy you dinner and expect sexual favours in return.
The trio of researchers discovered that many people seemed to be curious about the sex lives of others. Individuals who had a high degree of sexual narcissism were very susceptible to comparisons with others, regardless of whether the source was friends, colleagues, survey data or magazine articles. They tended to make comparisons favourable to themselves (downward comparisons). Comparisons that showed them in a lesser light (upward comparisons) appeared to decrease their satisfaction, both with their sexual relationship and their overall relationship.
“Individuals with a high degree of sexual narcissism tend to make comparisons with those who are less sexually skilled, for example,” Day said. “When they do make comparisons with someone doing better than they were, it gets under their skin.”
By contrast, individuals with a low degree of sexual narcissism weren’t much affected by favourable comparisons; they didn’t have much of an impact on how sexually satisfied they were or how much satisfaction they derived from their relationships.
The researchers reached these conclusions through three studies that used participants from the Amazon survey roster. In the each study, the participants were measured for sexual narcissism and for personality narcissism. In the first study, participants were then asked to recall the most recent comparison they had made between their sex lives and that of others – data show that people make such comparisons on five per cent of the days in the year.
The researchers assessed the direction of these comparisons. “People who were higher in sexual narcissism were more likely to recall a [favourable] social comparison, which in turn predicted greater sexual and relationship satisfaction immediately after recalling that comparison,” they wrote.
In the second study, the researchers asked the participants how much they would be bothered by sexual comparisons with those who had more prowess or more regular sexual relations if those people were: (a) their best friend, (b) their partner’s best friend, and (c) the average couple. The results, wrote the researchers, “showed that people who were higher in sexual narcissism reported that they would be more bothered by upward social comparisons, and, in turn, reported lower sexual and relationship satisfaction.”
In the third study, subjects were given a doctored magazine article relating to sexuality and randomly asked to compare its findings to their own sex lives in an upward fashion, a downward fashion or not to make any comparison. They were then asked about their satisfaction with their personal relationships and their sexual relationships. As anticipated, those with a high degree of sexual narcissism were very sensitive to such comparisons and were dissatisfied with their sexual and personal relationships when forced to compare themselves in a non-favourable way.
“People are curious about the sexuality of others and make comparisons that impact how they feel about their own relationships,” Day said. “This curiosity has opened a completely new line of research for us.”
The role of human sex outside of reproduction remains something of an evolutionary mystery. But scientists believe that it is partly about tying the parties in the relationship together.
[H]ow often women in heterosexual couples desire sex depends on how committed the relationship is and what type of birth control the woman uses.
Sex is quite wonderful when the goal is to have children. But sex can also serve as a “glue” in a committed relationship.
Most animals have periods when they come into heat, and outside of these periods they don’t find sex interesting at all.
Humans, however, are constantly interested in sex. This interest can seem like a waste of energy, but an evolutionary perspective may explain why we function this way.
More sex with progesterone and commitment
A new study from NTNU and the University of New Mexico confirm that sex is important for pair–bonding between men and women in relationships.
The researchers also found a correlation between the type of oral contraceptive women use and how often couples have sex.
The findings were recently published in the scientific journal Evolution & Human Behavior.
“The function of sex in humans outside ovulation is an evolutionary mystery. But we believe that it has to do with binding the parties in the relationship together,” says Leif Edward Ottesen Kennair, a professor of psychology at NTNU.
Kennair worked with Trond Viggo Grøntvedt, Nick Grebe and University of New Mexico Professor Steve Gangestad to ask hundreds of Norwegian heterosexual women about contraception, sex and relationships.
Their results show that of women in long-term relationships and who are using hormonal contraception, those who are more committed to their relationships have more sex with partners, as one might expect.
“But this association was especially true when the contraceptive that women used had potent levels of synthetic hormones that mimic the effects of the natural hormone progesterone, and lower levels of the hormone oestrogen,” Gangestad said.
“We’re talking about intercourse here, not other types of sex like oral sex, masturbation and such. This strengthens the idea that sex outside the ovulation phase has a function besides just pleasure,” says Grøntvedt.
Big differences between types of contraceptives
Hormonal contraceptives, like birth control pills, implantable rods and patches, contain two types of hormones:
Oestrogen, which naturally peaks just before ovulation when naturally cycling women can conceive offspring, and hormones that have the same effect as progesterone, which naturally peaks during the extended sexual phase, a time when offspring cannot be conceived.
The levels of each hormone type vary in different contraceptives. Hence, some contraceptives mimic hormones that are more characteristic of ovulation, whereas others mimic hormones when women can’t conceive.
The women who used contraception with more oestrogen were most sexually active when they were in a less committed relationship.
On the other hand, women who used contraception with more progesterone were the most sexually active when they were faithful and loyal to their partners.
“Before we did this study, we didn’t know how much difference there was between the two types of hormonal contraceptives,” says Grøntvedt.
A credible holistic picture
The researchers surveyed two groups of women. All the women were using hormonal contraception and were in committed, heterosexual relationships.
One group consisted of 112 women that researchers followed over a 12-week period. The women were asked how often and when in their cycle they had sex.
The second sample group consisted of 275 women in long–term relationships who used hormonal contraception.
This group was not followed over time, but the researchers asked them how many times they had had sex in the past week. This type of study – using data collected at a specific point in time – is called a cross-sectional study.
Both groups were asked to indicate the type of contraception they were using, and if a pill, which brand it was.
“Since we examined these two groups using different methods – a snapshot for the one group and a longitudinal study for the other – we can be confident that the results provide a reliable overall picture,” Grøntvedt said.
Natural or synthetic hormones had similar effects
The basis for the NTNU study was a 2013 American study, where 50 women and their partners answered a series of questions about their relationships, menstrual cycles and frequency of sex.
None of these women were using any kind of hormonal contraception, so only their natural hormones were involved.
The study showed that women initiated sex more in the extended sexual phase – when they were not ovulating and progesterone was the dominant hormone – if they were invested in the relationship.
NTNU researchers wanted to verify the American results in their study, but with participants who were using a hormonal contraceptive that simulates a natural cycle.
Their results were the same as in the US study, in which women were not using any hormonal birth control.
The researchers were thus able to show that how often women have sex is linked to how committed they feel towards their partner and the type of hormone they are governed by, whether natural or synthetic.
“A lot of social psychology studies that have led to cool discoveries through the ages have lost status, because it hasn’t been possible to copy them and verify the results.”
“We are extremely pleased to have been able to verify the results of the study by Grebe and his colleagues, and we are equally pleased that we have also made new discoveries,” Kennair says.
A ‘chocolate hormone’ could help to get couples in the mood for sex and fall more deeply in love.
[K]isspeptin, which is named after a chocolate snack, is the hormone in the brain which kickstarts puberty.
And it may explain something about the behaviour of teenage boys, after scientists found it makes men much more interested in sex and relationships.
Young men injected with the hormone and then given brain scans showed a flurry of activity in the parts of the brain activated by sexual arousal and romance. It means similar injections could be used to help men to start a family.
Professor Waljit Dhillo, the lead author of the research from Imperial College London, said: ‘Our initial findings are novel and exciting as they indicate that kisspeptin plays a role in stimulating some of the emotions and responses that lead to sex and reproduction.
‘Ultimately, we are keen to look into whether kisspeptin could be an effective treatment for psychosexual disorders, and potentially help countless couples who struggle to conceive.’
One in 10 men in the UK are believed to have sexual problems, many suffering a lack of libido caused by relationship issues, stress and anxiety.
This can cause problems for couples trying for a child and advised to have regular sex throughout the month.
But kisspeptin is hoped to hold the answer, following a trial involving 29 healthy young men.
Those injected with kisspeptin, discovered in the mid-1990s in Hershey, Pennsylvania, and named after sweets from the city called Hershey’s Chocolate Kisses, reacted differently to sexual and non-sexual romantic pictures of couples.
In an MRI scanner, where their brains were monitored, there was greater activity in the parts of the brain typically activated by sexual arousal and romance than the men given a placebo.
Professor Dhillo said: ‘Most of the research and treatment methods for infertility to date have focused on the biological factors that may make it difficult for a couple to conceive naturally.
‘These of course play a huge part in reproduction, but the role that the brain and emotional processing play in this process is also very important, and only partially understood.’
The effect is likely to come from kisspeptin’s role in starting puberty, by stimulating the release of reproductive hormones.
A study from Edinburgh University previously found it fuels the production of testosterone, which is key to male libido and fertility
The researchers now want to study how the hormone affects women as well as men, while kisspeptin might also work as an antidepressant.
Volunteers shown negative and fearful emotional faces in pictures said they felt less bad in follow-up questionnaires after receiving the hormone, with less activity in brain structures important in regulating a bad mood.
Dr Alexander Comninos, first author of the study at Imperial, said: ‘Our study shows that kisspeptin boosts sexual and romantic brain activity as well as decreasing negative mood.
‘This raises the interesting possibility that kisspeptin may have uses in treating psychosexual disorders and depression which are major health problems which often occur together, but further studies would be needed to investigate this.’
This year has been memorable for a lot of reasons, but one that may not be immediately obvious is that we learned a lot about the science of sex in 2016. Among other things, sex researchers brought us one step closer to a male version of the birth control pill, they debunked the idea that porn kills love, and they discovered that having a cat just might make you more inclined toward kinky sex (yep, you read that right). Let’s take a closer look at these findings and some of the other fascinating things scientists taught us about sex in 2016.
Americans are warming up to the idea of open relationships.
Americans are more interested than ever in consensual non-monogamy (CNM), or the practice of having multiple sexual and/or romantic relationships at the same time. A study published in The Journal of Sex Research in May found that Google searches for two forms of CNM—open relationships and polyamory—have significantly increased across the past decade. At the same time, a study published in the Journal of Sex & Marital Therapy found that more people are practicing CNM than previously thought: in a nationally representative survey of single Americans, more than 1 in 5 said they had been in a sexually open relationship before. Table for more than two, please.
We’re getting closer to a male version of the birth control pill.
An October study from The Journal of Clinical Endocrinology & Metabolism reported the results of a clinical trial in which men were given hormone injections designed to suppress their sperm production. The results were stunning: over the course of a year, the pregnancy rate for couples taking part in the study was just 1.57 out of 100. Unfortunately, however, the rate of side effects was very high, which led an external review board to recommend shutting down the study. Although this injection won’t be hitting the market, this study provides optimism that we’re not too far off from having a male equivalent of the female birth control pill.
Millennials are identifying as LGB at much higher rates than Gen Xers.
In January, the CDC released a report revealing major generational differences in Americans’ sexual identities. Specifically, millennials aged 18-24 were almost twice as likely to identify as gay, lesbian, or bisexual than Gen Xers aged 35-44. Millennials were more likely to report having engaged in same-sex behavior, too. However, whether this means same-sex attraction is actually increasing or if it’s just a sign that younger folks are more comfortable acknowledging their non-heterosexuality, we can’t say for sure.
The HPV vaccine has been wildly effective at reducing cancer.
In August, scientists reported that, in the ten years since the first vaccine for the human papilloma virus (HPV) was administered, rates of cervical cancer have been halved. If we can increase vaccination rates even further, there’s a chance that HPV-related cancers—including those of the cervix, anus, throat, and penis—could be eradicated within just a few decades.
Porn doesn’t change how men feel about their relationships.
A classic study from the 1980s found that heterosexual married men reported less love for their wives after viewing images of sexy magazine centerfolds compared to images of abstract art. This year, researchers tried three times to replicate the effect, but found nothing. Nada. Zip. Zero. These findings suggest that porn probably doesn’t kill love after all.
BDSM acts can produce an altered state of consciousness.
In May, a study published in the journal PLOS ONE looked at the psychological experiences of people who took part in an extreme masochistic ritual in which their skin was pierced with hooks that had weights attached. These participants demonstrated evidence of an altered mental state known as transient hypofrontality, described as “reductions in pain, living in the here and now, little active decision making, little active logic, and feelings of floating and peacefulness.” This suggests that BDSM acts have the potential to be a very spiritual experience.
We might be able to treat low sexual desire by electrically stimulating the brain.
In a November study published in the journal PLOS ONE, researchers found that delivering electrical stimulation to the brain changes the way we respond to sexual stimulation. Specifically, a targeted cranial “zap” appears to enhance the response that occurs in the brain’s pleasure centers. This suggests that we might actually be able to use brain stimulation as a treatment for people who complain of low sexual desire in the not too distant future.
Sexual arousal puts us in a risk-taking state of mind.
A January study published in the Archives of Sexual Behavior reveals that being horny can make us susceptible to taking risks, including those that are both sexual and non-sexual. In one study, participants who watched an X-rated film subsequently expressed more willingness to keep having sex after noticing a broken condom. In another study, sexually aroused participants made riskier moves in a game of computerized blackjack. These findings suggest that, when we’re feeling hot and bothered, well, we can’t be bothered to properly evaluate risks.
Women can detect when other women are ovulating, an ability they might use to protect their relationships.
In an April study published in the Journal of Personality and Social Psychology, researchers showed female participants photos of a woman who was either ovulating or not. Those who saw an ovulating woman were the most worried about keeping their partners away from her, but this was only true for participants with attractive partners. This suggests that women may have evolved the ability to pick up on other women’s ovulation status as a means of helping them to guard desirable mates from potential relationship threats.
Having a cat might increase your interest in kinky sex.
A July study published in the journal Evolutionary Psychology reported that people’s attraction to kinky sex depended upon whether they had been infected with toxoplasmosis, a parasitic disease that can be passed from cats to humans. Specifically, those who said they had been infected were more into bondage, violence, zoophilia, and fetishism. Why is that? The researchers suspect that it’s because this infection affects the circuits of the brain involved in fear, given that in mice and rats, toxoplasmosis switches their natural fear of cat smell into an attraction toward it.
Here’s to hoping 2017 is another mind-blowing year for sex research!
[M]any of us call erections “boners,” although there’s no actual bone in the penis. This bone has been the subject of many debates as several animals have them in diverse sizes and lengths, but humans don’t. Evolutionary scientists at the University College London suggest this strange anomaly is a consequence of monogamy and quick sex.
The penis bone, also known as the “baculum,” evolved in mammals more than 95 million years ago, and was spotted in the first primates that emerged about 50 million years ago, according to the researchers. The baculum became larger in some animals and smaller in others. For example, in the walrus, it can be two feet long, while in a monkey it’s about the length of a human fingernail.
Previous research has found the penis bone increases the potential duration of intercourse, and the frequency with which sex can take place. A lioness can copulate 100 times per day, sometimes with only four-minute intervals, but has just a 38 percent conception rate. This means males need to have better sexual stamina to achieve the best chance of paternity.
So, why do humans lack a penis bone?
The recent study, published in Proceedings of the Royal Society, found a link between penis bone length, promiscuity, and sex duration. Some species have longer penis bones because they engage in “prolonged intromission,” which means the act of penetration lasts for more than three minutes. Longer intromission times are more common among polygamous mating species, where multiple males mate with multiple females, like bonobos and chimps. This mating system creates an intense competition for fertilization, and reduces a female’s access to more mates by having males spend more time having sex with them, according to the study.
The penis bone is attached at the tip of the penis rather than the base to provide structural support for animals who do prolonged intromission, and to keep the urethra open.
The researchers believe humans lost their penis bones when monogamy became a dominant reproductive strategy about 1.9 million years ago.
“We think that is when the human baculum would have disappeared because the mating system changed at that point,” Kit Opie, a co-author of the study at University College London, told The Guardian.
Opie and his colleague Miranda Brindle believe the male does not need to spend a long time penetrating the female since she is not likely to be leapt by other amorous males. Therefore, the reduction of competition for mates means humans are less likely to need a penis bone. Opie adds, despite popular belief, humans do not generally need longer than three minutes to get the job done, and successfully impregnate a woman.
“We are actually one of the species that comes in below the three minute cut-off where these things come in handy,” he said.
Scientists have just begun to put together the function of this mysterious bone. They do agree changes in the penis bone are driven as part of a mating strategy. This means a bigger penis bone is better when it comes to sexual competition.
Human males, do not feel bad — if the penis bone is damaged, it could take as long as other broken bones to heal.
Engaging in kinky sex may send you into an altered state of consciousness and even unlock your inner creativity, according to a new study. The research also suggests BDSM reduces psychological stress, improves moods, and increases sexual arousal.
[E]ngaging in kinky sex may send you into an altered state of consciousness and even unlock your inner creativity, according to a new study.
Using a small sample of participants from the kink-focused social network Fetlife, researchers investigated the mind-altering effects of BDSM – bondage/discipline, dominance/submission, and sadism/masochism.
Not only were these activities found to produce two types of altered states, but research suggests BDSM also reduces psychological stress, improves moods, and increases sexual arousal.
While previous studies have attempted to investigate this phenomena, no other research has actually put it to the test, the researchers explain in a paper published to the journal Psychology of Consciousness: Theory, Research, and Practice.
So, researchers from the Science of BDSM Research Team at Northern Illinois University recruited seven pairs of self-identified ‘switches’ – people who were willing to be randomly assigned to either a top or bottom role in a BDSM scene.
This way, the researchers explain, the differences observed in the study could be better attributed to the role rather than the individual.
Fourteen people participated in total, with 10 women and four men between the ages of 23 and 64.
For the experiments, the participants partook in seven scenes which involved everything from gentle touching and communication to striking, bondage, and fetish dress.
Each of the participants provided five saliva samples throughout the experiments, and were asked to complete three Stroop tests, involving words and colours: one prior to their assignment, one before the scene, and one after it had ended.
The test measured for an altered state of consciousness aligned with Dietrich’s transient hypofrontality, which relates to daydreaming, runner’s high, meditation, and even some drug highs.
Along with this, the participants were also given a measure of mental ‘flow’ following each scene, using the Flow State Scale ranging from ‘strongly disagree’ to ‘strongly agree.’
Flow is a nine-dimensional altered state conceptualized by Csikszentmihalyi, and is achieved during ‘optimal experiences,’ the researchers explain.
The dimensions of flow include ‘challenge-skill balance, action-awareness merging, clear goals, unambiguous feedback, concentration on task, sense of control, loss of self-consciousness, time transformation,’ and feelings of intrinsic reward.
The experiments revealed that the bottom role and the top role in BDSM are each associated with a distinct altered state of consciousness, both of which have previously been tied to creativity.
According to the researchers, ‘topping’ is linked to the state which aligned with Csikszentmihalyi’s flow, while ‘bottoming’ is associated with both Dietrich’s transient hypofrontality and some aspects of flow.
The team says these activities also reduced stress and negative affect in the participants, and increased sexual arousal.
While BDSM has long been a stigmatized practice, the authors say the finding support the idea that there are numerous factors driving these preferences that do not relate to mental disorder.
‘The results contribute to a growing body of evidence that individuals pursue BDSM for nonpathological reasons,’ the researchers conclude, ‘including the pleasant altered states of consciousness these activities are theorized to produce.’
A new study by Northern Illinois University psychologists suggests that evidence for the effectiveness of the “Yes Means Yes” affirmative-consent movement, which has taken hold on many college campuses nationwide, might be found in an unlikely subculture—the BDSM community.
While some critics of BDSM associate it with sexual aggression, and particularly violence against women, the subculture has had long-standing norms of affirmative consent, the researchers said. Their study found BDSM practitioners also report lower levels of rape-supportive beliefs than individuals surveyed from outside the subculture.
The psychologists used an online survey to measure the level of rape-supportive beliefs of 185 individuals from three groups—college students, random online respondents and BDSM practitioners.
BDSM practitioners reported significantly lower levels of “benevolent sexism,” “rape myth acceptance” and “victim blaming”— elements of what feminists and other researchers have proposed as being part of a larger rape culture that tolerates and even glorifies male sexual aggression against women.
Benevolent sexism is a chivalrous but also sexist attitude toward women, casting them as pure but fragile. Rape myths are inaccurate beliefs about rape, such as “women secretly want men to sexually dominate them” or “women incite men to rape by flirting with them.” Victim-blaming attitudes shift full or partial blame for sexual assault to the victim, such as “she was asking for it.”
The study was led by Kathryn Klement, an NIU doctoral student in psychology. A summary is available online ahead of print publication in the Journal of Sex Research.
Klement said the idea for the research survey was prompted by criticisms of the “Yes Means Yes” movement and related affirmative-consent policies and laws. The movement challenges sexual partners to explicitly communicate with each other about their desires prior to sexual activity.
In 2014, California began requiring college campuses to use an affirmative definition of consent. Many college and university campuses, and several other states (including Illinois), have adopted similar policies or laws. While the movement aims to stem the prevalence of sexual assault, it hasn’t been universally embraced.
“Affirmative consent contrasts with what we see in movies, TV shows and other media that often portray sex without communication,” Klement said. “Some critics have said ‘Yes Means Yes’ would make sex less sexy.”
The researchers hypothesized that BDSM practitioners would have lower levels of rape-supportive beliefs because of the subculture’s longstanding norms of affirmative consent through negotiation, when participants establish boundaries for sexual and BDSM activities and “safe words” to curtail or end activity.
“We wanted to look at attitudes in a subculture where consent and negotiation are normalized and accepted, yet people aren’t having less sex,” Klement said. “It made sense that this group of people might be more egalitarian, even though that seems paradoxical in a community that’s basically based on power exchange.”
The study, which controlled for age differences, indeed found significantly lower levels of rape-supportive beliefs among BDSM practitioners on three of six measures (with no significant differences among the survey groups on the remaining three).
“Negotiating about sex beforehand doesn’t make it any less sexy,” Klement said. “Consent is the critical element that separates healthy sexual encounters from assault.”
Klement said this point is especially important in light of other recent research, which shows college men and women report some differences in how they indicate and interpret consent from their sexual partners.
Co-authors on the NIU study include Ellen Lee, an NIU doctoral student in psychology, and Brad Sagarin, an NIU psychology professor who conducts research on the science of BDSM. Sagarin said that while the study clearly found an association between BDSM and lower rape-supportive beliefs, more research is needed to determine why that correlation exists.
“This was a correlational study, so we don’t know for certain why members of the BDSM community report lower levels of rape-supportive beliefs,” he said. “Nevertheless, it’s a first step in understanding another potential benefit of affirmative consent.”
In addition to how the study’s findings might relate to the practice of affirmative consent, Sagarin said there is another takeaway.
“The BDSM community has historically been stereotyped,” he said. “When you see a sexual sadist on TV, he is typically not a good guy.
“I think this study helps break the stigma of BDSM practitioners as bad or damaged people,” he added.
In the last two decades, dozens of scientific papers have been published on the biological origins of homosexuality – another announcement was made last week. It’s becoming scientific orthodoxy. But how does it fit with Darwin’s theory of evolution?
Macklemore and Ryan Lewis’s hit song Same Love, which has become an unofficial anthem of the pro-gay marriage campaign in the US, reflects how many gay people feel about their sexuality.
It mocks those who “think it’s a decision, and you can be cured with some treatment and religion – man-made rewiring of a predisposition”. A minority of gay people disagree, maintaining that sexuality is a social construct, and they have made a conscious, proud choice to take same-sex partners.
But scientific opinion is with Macklemore. Since the early 1990s, researchers have shown that homosexuality is more common in brothers and relatives on the same maternal line, and a genetic factor is taken to be the cause. Also relevant – although in no way proof – is research identifying physical differences in the brains of adult straight and gay people, and a dizzying array of homosexual behaviour in animals.
But since gay and lesbian people have fewer children than straight people, a problem arises.
“This is a paradox from an evolutionary perspective,” says Paul Vasey from the University of Lethbridge in Canada. “How can a trait like male homosexuality, which has a genetic component, persist over evolutionary time if the individuals that carry the genes associated with that trait are not reproducing?”
Scientists don’t know the answer to this Darwinian puzzle, but there are several theories. It’s possible that different mechanisms may be at work in different people. Most of the theories relate to research on male homosexuality. The evolution of lesbianism is relatively understudied – it may work in a similar way or be completely different.
The genes that code for homosexuality do other things too
The allele – or group of genes – that sometimes codes for homosexual orientation may at other times have a strong reproductive benefit. This would compensate for gay people’s lack of reproduction and ensure the continuation of the trait, as non-gay carriers of the gene pass it down.
There are two or more ways this might happen. One possibility is that the allele confers a psychological trait that makes straight men more attractive to women, or straight women more attractive to men. “We know that women tend to like more feminine behavioural features and facial features in their men, and that might be associated with things like good parenting skills or greater empathy,” says Qazi Rahman, co-author of Born Gay; The Psychobiology of Sex Orientation. Therefore, the theory goes, a low “dose” of these alleles enhances the carrier’s chances of reproductive success. Every now and then a family member receives a larger dose that affects his or her sexual orientation, but the allele still has an overall reproductive advantage.
Another way a “gay allele” might be able to compensate for a reproductive deficit is by having the converse effect in the opposite sex. For example, an allele which makes the bearer attracted to men has an obvious reproductive advantage to women. If it appears in a man’s genetic code it will code for same-sex attraction, but so long as this happens rarely the allele still has a net evolutionary benefit.
There is some evidence for this second theory. Andrea Camperio-Ciani, at the University of Padova in Italy, found that maternal female relatives of gay men have more children than maternal female relatives of straight men. The implication is that there is an unknown mechanism in the X chromosome of men’s genetic code which helps women in the family have more babies, but can lead to homosexuality in men. These results haven’t been replicated in some ethnic groups – but that doesn’t mean they are wrong with regards to the Italian population in Camperio-Ciani’s study.
Gay people were ‘helpers in the nest’
The fa’afafine of Samoa dislike being called “gay” or “homosexual”
Some researchers believe that to understand the evolution of gay people, we need to look at how they fit into the wider culture.
Paul Vasey’s research in Samoa has focused on a theory called kin selection or the “helper in the nest” hypothesis. The idea is that gay people compensate for their lack of children by promoting the reproductive fitness of brothers or sisters, contributing money or performing other uncle-like activities such as babysitting or tutoring. Some of the gay person’s genetic code is shared with nieces and nephews and so, the theory goes, the genes which code for sexual orientation still get passed down.
Sceptics have pointed out that since on average people share just 25% of their genetic code with these relatives, they would need to compensate for every child they don’t have themselves with two nieces or nephews that wouldn’t otherwise have existed. Vasey hasn’t yet measured just how much having a homosexual orientation boosts siblings’ reproduction rate, but he has established that in Samoa “gay” men spend more time on uncle-like activities than “straight” men.
“No-one was more surprised than me,” says Vasey about his findings. His lab had previously shown that gay men in Japan were no more attentive or generous towards their nieces and nephews than straight, childless men and women. The same result has been found in the UK, US and Canada.
Vasey believes that his Samoan result was different because the men he studied there were different. He studied the fa’afafine, who identify as a third gender, dressing as women and having sex with men who regard themselves as “straight”. They are a transgender group who do not like to be called “gay” or “homosexual”.
Vasey speculates that part of the reason the fa’afafine are more attentive to their nephews and nieces is their acceptance in Samoan culture compared to gay men in the West and Japan (“You can’t help your kin if they’ve rejected you”). But he also believes that there is something about the fa’afafine way of life that means they are more likely to be nurturing towards nieces and nephews, and speculates that he would find similar results in other “third gender” groups around the world.
If this is true, then the helper in the nest theory may partly explain how a genetic trait for same-sex attraction hasn’t been selected away. That hypothesis has led Vasey to speculate that the gay men who identify as men and have masculine traits – that is to say, most gay men in the West – are descended from men who had a cross-gendered sexuality.
These figures may not be high enough to sustain genetic traits specific to this group, but the evolutionary biologist Jeremy Yoder points out in a blog post that for much of modern history gay people haven’t been living openly gay lives. Compelled by society to enter marriages and have children, their reproduction rates may have been higher than they are now.
How many gay people have children also depends on how you define being “gay”. Many of the “straight” men who have sex with fa’afafine in Samoa go on to get married and have children.
“The category of same-sex sexuality becomes very diffuse when you take a multicultural perspective,” says Joan Roughgarden, an evolutionary biologist at the University of Hawaii. “If you go to India, you’ll find that if someone says they are ‘gay’ or ‘homosexual’ then that immediately identifies them as Western. But that doesn’t mean there’s no homosexuality there.”
Similarly in the West, there is evidence that many people go through a phase of homosexual activity. In the 1940s, US sex researcher Alfred Kinsey found that while just 4% of white men were exclusively gay after adolescence, 10% had a three-year period of gay activity and 37% had gay sex at some point in their lives.
A national survey of sexual attitudes in the UK last year came up with lower figures. Some 16% of women said they had had a sexual experience with another woman (8% had genital contact), and 7% of men said they had had a sexual experience with a man (with 5% having genital contact).
But most scientists researching gay evolution are interested in an ongoing, internal pattern of desire rather than whether people identify as gay or straight or how often people have gay sex. “Sexual identity and sexual behaviours are not good measures of sexual orientation,” says Paul Vasey. “Sexual feelings are.”
It’s not all in the DNA
Qazi Rahman says that alleles coding for same sex attraction only explain some of the variety in human sexuality. Other, naturally varying biological factors come into play, with about one in seven gay men, he says, owing their sexuality to the “big brother effect”.
This has nothing to do with George Orwell, but describes the observation that boys with older brothers are significantly more likely to become gay – with every older brother the chance of homosexuality increases by about a third. No-one knows why this is, but one theory is that with each male pregnancy, a woman’s body forms an immune reaction to proteins that have a role in the development of the male brain. Since this only comes into play after several siblings have been born – most of whom are heterosexual and go on to have children – this pre-natal quirk hasn’t been selected away by evolution.
Exposure to unusual levels of hormone before birth can also affect sexuality. For example, female foetuses exposed to higher levels of testosterone before birth show higher rates of lesbianism later on. Studies show that “butch” lesbian women and men have a smaller difference in length between their index and ring fingers – a marker of pre-natal exposure to testosterone. In “femme” lesbians the difference has been found to be less marked.
Brothers of a different kind – identical twins – also pose a tricky question. Research has found that if an identical twin is gay, there is about a 20% chance that the sibling will have the same sexual orientation. While that’s a greater likelihood than random, it’s lower than you might expect for two people with the same genetic code.
William Rice, from the University of California Santa Barbara, says that it may be possible to explain this by looking not at our genetic code but at the way it is processed. Rice and his colleagues refer to the emerging field of epigenetics, which studies the “epimarks” that decide which parts of our DNA get switched on or off. Epimarks get passed on to children, but only sometimes. Rice believes that female foetuses employ an epimark that makes them less sensitive to testosterone. Usually it’s not inherited, but occasionally it is, leading to same-sex preference in boys.
Dr William Byne, editor-in-chief of the journal LGBT Health, believes sexuality may well be inborn, but thinks it could be more complicated than some scientists believe. He notes that the heritability of homosexuality is similar to that for divorce, but “social science researchers have not… searched for ‘divorce genes’. Instead they have focused on heritable personality and temperamental traits that might influence the likelihood of divorce.”
For Qazi Rahman, it’s the media that oversimplifies genetic theories of sexuality, with their reports of the discovery of “the gay gene”. He believes that sexuality involves tens or perhaps hundreds of alleles that will probably take decades to uncover. And even if heterosexual sex is more advantageous in evolutionary terms than gay sex, it’s not only gay people whose sexuality is determined by their genes, he says, but straight people too.
In the Dominican Republic, the phenomenon of children who were raised female appearing to swap sexes at puberty is so common it even has a name. Guevedoces roughly translates to “penis [or “balls”] at 12,” and it’s the result of a rare enzyme deficiency that delays crucial steps of male sexual development until puberty.
When guevedoces are born, they appear to have external female genitalia even though their genes and internal reproductive organs are male. Parents assume their children are girls and raise them as such. But when these children begin producing large amounts of testosterone at puberty, their testes descend and they grow a penis—in addition to all the other changes that come along with male adolescence.
Sexual development normally begins in the womb, and the same is true for guevedoces. Whether the fetus has one X chromosome or two, for the first several weeks of development its genes follow the same blueprint for both sexes. Then, sometime around the eight-week mark, the sex chromosomes get to work. For males, the undeveloped gonads become testicles and they start to release male hormones, including testosterone. In a structure called the tubercle, an enzyme called 5-alpha-reductase converts the testosterone to a stronger hormone called dihydrotestosterone (DHT), which is necessary to develop external genitalia. It’s this hormone that turns the tubercle into a penis; without it, it develops into a clitoris.
The rare enzyme deficiency found in guevedoces leaves them unable to develop external male genitalia in the womb. They still produce plenty of testosterone, which triggers the development of internal structures like the epididymis and vas deferens, but the lack of DHT makes the babies appear female at birth. It’s not until the second surge of testosterone these children receive at puberty that they grow testes and a penis.
The condition is thought to be genetic, tracing back to the female founder of a small village in the Dominican Republic’s mountainous hinterland. Outside of the nation, it’s incredibly rare.
For some guevedoces, being raised as female wasn’t an easy experience. “I never liked to dress as a girl, and when they bought me toys for girls, I never bothered playing with them,” Johnny, who had grown up as Felicita, told BBC Two, which features these kids in the second episode of the series Countdown to Life: The Extraordinary Making of You. “When I saw a group of boys, I would stop to play ball with them.” When Johnny, now 24, began to undergo physical changes, he was taunted at school and called nasty names by his classmates. He’s had a number of short-term girlfriends since going through puberty and dreams of one day getting married and starting a family. Another child named Carla began the process of transitioning to Carlos at age 9; he can be seen receiving a smile-inducing haircut in the photo above.
Most people with this condition live out their adult lives as men, but some choose to undergo surgery and remain female. The discovery of this disorder in the 1970s led to the development of a best-selling drug called finasteride, which is commonly prescribed to treat benign enlargement of the prostate and male pattern baldness. (You may know it by the brand name Propecia.) The drug mimics the enzyme deficiency by blocking the action of 5-alpha-reductase.
Participants in a “No Trousers Day” flashmob ride the London Underground in 2012.
A study suggests people find expansive, space-consuming postures more romantically attractive
Manspreading might make you the villain of the morning L train, but a new study suggests it could also make you lucky in love. People who adopted “expansive postures”—widespread limbs and a stretched-out torso—in speed-dating situations garnered more romantic interest than those who folded their arms in “closed postures,” the researchers found.
For her recent paper, published this week in Proceedings of the National Academy of Sciences, Tanya Vacharkulksemsuk, a post-doctoral research fellow at the University of California, Berkeley, performed two studies. First, she and her team watched videos of 144 speed-dates and correlated them with the participants’ ratings of each other. People who sat in expanded postures were deemed more attractive, and for both men and women, postural expansiveness nearly doubled their chances of getting a “yes” response to a second date. Even laughing and smiling didn’t work as well as spreading out, Vacharkulksemsuk found.
Examples of expansive postures used in the study
Next, Vacharkulksemsuk posted pictures of people in open and closed postures on a dating site. Again, those in the expansive postures were about 25 percent more likely to generate interest from another user. However, this strategy worked much better for men than women. Men, overall, received far fewer bites than women did, but 87 percent of their “yesses” came in response to an open posture. For women, meanwhile, 53 percent of “yes” responses came when they were in an expansive posture.
Examples of contractive postures used in the studyIn a separate test, Vacharkulksemsuk found that both the male and female “expansive” photos were considered more dominant than the “closed” photos. That dominance might suggest an abundance of resources and a willing to share those resources. When potential romantic partners are evaluating each other for just a few seconds, in other words, money talks—mainly through bodily breadth.
So should you rush to change your Tinder picture to something a little less pouty and a little more Backstreet Boys cira Millennium? Like with almost every study, there are reasons to be skeptical. “Power poses” made a big splash in 2010 when it was found that adopting them could tweak hormone levels—then sparked controversy after a follow-up study failed to replicate the effect.
Several researchers who weren’t involved with the study expressed doubts about its methodology. Agustín Fuentes, a professor of anthropology at the University of Notre Dame, said the findings might be a sign of general social preference for openness, but not necessarily that open-looking poses are sexier. “The connection to mating/dating assessment they suggest is superficial,” he said in an email.
Irving Biederman, a professor of neuroscience at the University of Southern California, said some of the “expansive” women might have looked vulnerable, rather than powerful.
To Vacharkulksemsuk, though, the fact that her study subjects rated both the male and female “expansive” photos as dominant—and found that dominance attractive—might signal the start of something very exciting. For decades, women have been told they’re most attractive when they’re demure, high-pitched, and generally non-threatening. This data “may be signifying a change in what men are looking for in women,” she said. Perhaps commuters should brace themselves for the rise of fem-spreading.
Seattle Seahawks quarterback Russell Wilson and his girlfriend Ciara arrive at a White House State Dinner in April.
Seattle Seahawks quarterback Russell Wilson and his girlfriend, the singer Ciara, recently announced plans to remain sexually abstinent until marriage.
It was a vow that came as a surprise to many. After all, sexual purity is a commitment that is historically expected of, associated with – even demanded of – women. However, sexual abstinence is not something assumed of men, especially men like Russell Wilson.
Wilson, an accomplished, attractive athlete, embodies contemporary ideals of masculinity, which include style, wealth and, yes, sexual prowess.
So how does a man like Russell Wilson navigate a commitment to abstinence while upholding ideals of masculinity? Wilson’s status as an athlete and heartthrob is likely giving him what sociologist CJ Pascoe calls “jock insurance.” In other words, due to his celebrity status, he can make traditionally nonmasculine choices without having his masculinity questioned.
But what does it mean for a man who isn’t in the limelight, who makes a similar type of commitment to abstinence? And what does it mean for the women they date, and might eventually marry?
I’ve been researching men who pledge sexual abstinence since 2008, work that comes out of a larger scholarly interest in masculinities, religion and sex education.
While men make this commitment with the good intentions for a fulfilling marriage and sex life, my research indicates that the beliefs about sexuality and gender that come hand in hand with these pledges of abstinence do not necessarily make for an easy transition to a married sexual life.
Who’s Pledging “Purity?”
Comedian Joy Behar recently joked that abstinence is what you do after you’ve been married for a long time. Here, Behar makes two assumptions. One is that sexual activity declines both with age and the time spent in a relationship. This is true.
The second is that abstinence is not something you do before marriage. For the most part, this is true as well: by age 21, 85% of men and 81% of women in the United States have engaged in sexual intercourse.
If we compare these numbers to the average age of first marriage in the United States – 27 for women, and 29 for men – we get the picture: most people are having sex before marriage.
Still, some in the United States are making “virginity pledges,” and commit to abstinence until marriage. Most of the data that exist on this practice show that those who make the pledges will do so in high school, often by either signing a pledge card or donning a purity ring.
Research on this population tells us a few things: that those who pledge are more likely to be young women, and that – regardless of gender – an abstinence pledge delays the onset of sexual activity by only 18 months. Furthermore, taking a virginity pledge will often encourage other types of sexual behavior.
Virgins In Guyland
But little is known about men who pledge and navigate this commitment to abstinence.
I was curious about how men maintain pledges in light of these statistics, and also balance them with expectations about masculinity. So in 2008, I began researching a support group of 15 men at an Evangelical church in the Southwest. All members were white, in their early to mid-20’s, single or casually dating – and supporting each other in their decisions to remain abstinent until marriage.
The group, called The River, met once a week, where, sitting on couches, eating pizza or talking about video games, they’d eventually gravitate toward the topic that brought them all together in the first place: sex.
On the surface, it would seem impossible for these men to participate in what sociologist Michael Kimmel calls “Guyland” – a developmental and social stage driven by a “guy code” that demands, among other things, sexual conquest and detached intimacy.
Rather, the men of The River approach sex as something sacred, a gift from God meant to be enjoyed in the confines of the marriage bed. At the same time, these men struggle with what they describe as the “beastly elements” – or temptations – of sexuality. And it is precisely because of these so-called beastly elements that these men find each other in the same space every week.
The men of The River grappled with pornography use, masturbation, lust and same-sex desire, all of which can potentially derail these men from their pledge.
It raises an interesting dilemma: to these men, sex is both sacred and beastly. Yet the way they navigate this seeming contradiction actually allows them to exert their masculinity in line with the demands of Guyland.
Group members had an elaborate network of accountability partners to help them resist temptations. For example, one had an accountability partner who viewed his weekly online browsing history to make sure he wasn’t looking at pornography. Another accountability partner texted him each night to make sure that he and his girlfriend were “behaving.”
While these behaviors may seem unusual, they work in ways that allow men to actually assert their masculinity. Through what sociologist Amy Wilkins calls “collective performances of temptation,” these men are able to discuss just how difficult it is to refrain from the beastly urges; in this way, they reinforce the norm that they are highly sexual men, even in the absence of sexual activity.
The River, as a support group, works largely in the same way. These men are able to confirm their sexual desires in a homosocial space – similar to Kimmel’s research in Guyland – from which Kimmel notes that the “actual experience of sex pales in comparison to the experience of talking about sex.”
A ‘Sacred Gift’ – With Mixed Returns
The men of The River believed that the time and work required to maintain these pledges would pay off in the form of a happy and healthy marriage.
Ciara, in discussing her commitment to abstinence with Russell Wilson, similarly added that she believes such a promise is important for creating a foundation of love and friendship. She stated that, “if we have that [base] that strong, we can conquer anything with our love.”
So what happened once after the men of The River got married? In 2011, I followed up with them.
All but one had gotten married. But while the transition to married life brought promises of enjoying their “sacred gift from God,” this gift was fraught.
Respondents reported that they still struggled with the beastly elements of sexuality. They also had the added concern of extramarital affairs. Furthermore – and perhaps most importantly – men no longer had the support to work through these temptations.
There were two reasons behind this development.
First, respondents had been told, since they were young, that women were nonsexual. At the same time, these men had also been taught that their wives would be available for their pleasure.
It’s a double standard that’s in line with longstanding cultural ideals of the relationship between femininity and purity. But it’s a contradiction that leaves men unwilling to open up to the very women they’re having sex with.
These married men and women were not talking to each other about sex. Rather than freely discussing sex or temptation with their wives (as they had done with their accountability partners), the men simply tried to suppress temptation by imagining the devastation any sexual deviations might cause their wives.
After marriage, the men felt left to their own devices.
Second, these men could no longer reach out to their support networks due to their own ideals of masculinity. They had been promised a sacred gift: a sexually active, happy marriage. Yet many weren’t fully satisfied, as evidenced by the continued tension between the sacred and beastly. However, to open up about these continued struggles would be to admit failure as masculine, Christian man.
In the end, the research indicates that a pledge of sexual abstinence works to uphold an ideal of masculinity that disadvantages both men and women.
After 25 years of being told that sex is something dangerous that needs to be controlled, the transition to married (and sexual) life is difficult, at best, while leaving men without the support they need. Women, meanwhile, are often left out of the conversation entirely.
So when we urge abstinence in place of healthy conversations about sex and sexuality, we may be undermining the relationships that are the driving goal of these commitments in the first place.
The media is hyping a study that doesn’t do what it says it does.
This week, a team from the University of California, Los Angeles claimed to have found several epigenetic marks—chemical modifications of DNA that don’t change the underlying sequence—that are associated with homosexuality in men. Postdoc Tuck Ngun presented the results yesterday at the American Society of Human Genetics 2015 conference. Nature News were among the first to break the story based on a press release issued by the conference organisers. Othersquicklyfollowedsuit. “Have They Found The Gay Gene?” said the front page of Metro, a London paper, on Friday morning.
Meanwhile, the mood at the conference has been decidedly less complimentary, with several geneticists criticizing the methods presented in the talk, the validity of the results, and the coverage in the press.
Ngun’s study was based on 37 pairs of identical male twins who were discordant—that is, one twin in each pair was gay, while the other was straight—and 10 pairs who were both gay. He analysed 140,000 regions in the genomes of the twins and looked for methylation marks—chemical Post-It notes that dictate when and where genes are activated. He whittled these down to around 6,000 regions of interest, and then built a computer model that would use data from these regions to classify people based on their sexual orientation.
The best model used just five of the methylation marks, and correctly classified the twins 67 percent of the time. “To our knowledge, this is the first example of a biomarker-based predictive model for sexual orientation,” Ngun wrote in his abstract.
The problems begin with the size of the study, which is tiny. The field of epigenetics is littered with the corpses of statistically underpowered studies like these, which simply lack the numbers to produce reliable, reproducible results.
Unfortunately, the problems don’t end there. The team split their group into two: a “training set” whose data they used to build their algorithm, and a “testing set”, whose data they used to verify it. That’s standard and good practice—exactly what they should have done. But splitting the sample means that the study goes from underpowered to really underpowered.
There’s also another, larger issue. As far as could be judged from the unpublished results presented in the talk, the team used their training set to build several models for classifying their twins, and eventually chose the one with the greatest accuracy when applied to the testing set. That’s a problem because in research like this, there has to be a strict firewall between the training and testing sets; the team broke that firewall by essentially using the testing set to optimise their algorithms.
If you use this strategy, chances are you will find a positive result through random chance alone. Chances are some combination of methylation marks out of the original 6,000 will be significantly linked to sexual orientation, whether they genuinely affect sexual orientation or not. This is a well-known statistical problem that can be at least partly countered by running what’s called a correction for multiple testing. The team didn’t do that. (In an email to The Atlantic, Ngun denies that such a correction was necessary.)And, “like everyone else in the history of epigenetics studies they could not resist trying to interpret the findings mechanistically,” wrote John Greally from the Albert Einstein College of Medicine in a blog post. By which he means: they gave the results an imprimatur of plausibility by noting the roles of the genes affected by the five epi-marks. One is involved in controlling immune genes that have been linked to sexual attraction. Another is involved in moving molecules along neurons. Could epi-marks on these genes influence someone’s sexual attraction? Maybe. It’s also plausible that someone’s sexual orientation influences epi-marks on these genes. Correlation, after all, does not imply causation.
So, ultimately, what we have is an underpowered fishing expedition that used inappropriate statistics and that snagged results which may be false positives. Epigenetics marks may well be involved in sexual orientation. But this study, despite its claims, does not prove that and, as designed, could not have.
In a response to Greally’s post, Ngun admitted that the study was underpowered. “The reality is that we had basically no funding,” he said. “The sample size was not what we wanted. But do I hold out for some impossible ideal or do I work with what I have? I chose the latter.” He also told Nature News that he plans to “replicate the study in a different group of twins and also determine whether the same marks are more common in gay men than in straight men in a large and diverse population.”Great. Replication and verification are the cornerstones of science. But to replicate and verify, you need a sturdy preliminary finding upon which to build and expand—and that’s not the case here. It may seem like the noble choice to work with what you’ve got. But when what you’ve got are the makings of a fatally weak study, of the kind well known to cause problems in a field, it really is an option—perhaps the best option—to not do it at all. (The same could be said for journalists outside the conference choosing to cover the study based on a press release.)As Greally wrote in his post: “It’s not personal about [Ngun] or his colleagues, but we can no longer allow poor epigenetics studies to be given credibility if this field is to survive. By ‘poor,’ I mean uninterpretable.”
“This is only representative of the broader literature,” he told me. “The problems in the field are systematic. We need to change how epigenomics research is performed throughout the community.”
Catherine and his cousin Carla, Guevedoces in the Dominican Republic
The discovery of a small community in the Dominican Republic, where some males are born looking like girls and only grow penises at puberty, has led to the development of a blockbuster drug that has helped millions of people, writes Michael Mosley.
Johnny lives in a small town in the Dominican Republic where he, and others like him, are known as “Guevedoces”, which effectively translates as “penis at twelve”.
We came across Johnny when we were filming for a new BBC Two series Countdown to Life, which looks at how we develop in the womb and how those changes, normal and abnormal, impact us later in life.
Like the other Guevedoces, Johnny was brought up as a girl because he had no visible testes or penis and what appeared to be a vagina. It is only when he approached puberty that his penis grew and testicles descended.
Johnny, once known as Felicita, remembers going to school in a little red dress, though he says he was never happy doing girl things.
“I never liked to dress as a girl and when they bought me toys for girls I never bothered playing with them – when I saw a group of boys I would stop to play ball with them.”
When he became obviously male he was taunted at school, and responded with his fists.
“They used to say I was a devil, nasty things, bad words and I had no choice but to fight them because they were crossing the line.”
We also filmed with Carla, who at the seven is on the brink of changing into Carlos. His mother has seen the change coming for quite a while.
“When she turned five I noticed that whenever she saw one of her male friends she wanted to fight with him. Her muscles and chest began growing. You could see she was going to be a boy. I love her however she is. Girl or boy, it makes no difference.”
So why does it happen? Well, one of the first people to study this unusual condition was Dr Julianne Imperato-McGinley, from Cornell Medical College in New York. In the 1970s she made her way to this remote part of the Dominican Republic, drawn by extraordinary reports of girls turning into boys.
When she got there she found the rumours were true. She did lots of studies on the Guevedoces (including what must have been rather painful biopsies of their testicles) before finally unravelling the mystery of what was going on.
When you are conceived you normally have a pair of X chromosomes if you are to become a girl and a set of XY chromosomes if you are destined to be male.
For the first weeks of life in womb you are neither, though in both sexes nipples start to grow.
Then, around eight weeks after conception, the sex hormones kick in. If you’re genetically male the Y chromosome instructs your gonads to become testicles and sends testosterone to a structure called the tubercle, where it is converted into a more potent hormone called dihydro-testosterone This in turn transforms the tubercle into a penis. If you’re female and you don’t make dihydro-testosterone then your tubercle becomes a clitoris.
When Imperato-McGinley investigated the Guevedoces she discovered the reason they don’t have male genitalia when they are born is because they are deficient in an enzyme called 5-alpha-reductase, which normally converts testosterone into dihydro-testosterone.
This deficiency seems to be a genetic condition, quite common in this part of the Dominican Republic, but vanishingly rare elsewhere. So the boys, despite having an XY chromosome, appear female when they are born. At puberty, like other boys, they get a second surge of testosterone. This time the body does respond and they sprout muscles, testes and a penis.
Imperato-McGinley’s thorough medical investigations showed that in most cases their new, male equipment seems to work fine and that most Guevedoces live out their lives as men, though some go through an operation and remain female.
Another thing that Imperato-McGinley discovered, which would have profound implications for many men around the world, was that the Guevedoces tend to have small prostates.
This observation, made in 1974, was picked up by Roy Vagelos, head of research at the multinational pharmaceutical giant, Merck. He thought this was extremely interesting and set in progress research which led to the development of what has become a best-selling drug, finasteride, which blocks the action of 5-alpha-reductase, mimicking the lack of dihydro-testosterone seen in the Guevedoces.
My wife, who is a GP, routinely prescribes finasteride as it is an effective way to treat benign enlargement of the prostate, a real curse for many men as they get older. Finasteride is also used to treat male pattern baldness.
This is still a controversial topic and one I explore later in the film when I meet Mati, who decided from the earliest age that though “he” looked like a boy, Mati was really a girl.
As for Johnny, since he developed male genitalia he has had a number of short term girlfriends, but he is still looking for love. “I’d like to get married and have children, a partner who will stand by me through good and bad,” he sighs wistfully.
A study by scientists at the University of Oslo found that larger testicles make less faithful couples
A study by scientists at the University of Oslo found that primates with bigger testicles were more likely to be unfaithful
There is a correlation between infidelity and the size of a male’s testicles, researchers have found.
A study by scientists at the University of Oslo found that primates with bigger testicles were more likely to be unfaithful.
Petter Bøckman, Assistant Professor, said: “We can determine the degree of fidelity in the female by looking at the size of the male’s testicles. The less faithful the female, the larger the male’s testicles.
“If the male will only fertilise one female and has no competitors, he only needs sufficient sperm to reach the egg. If the female mates on the side, it is smart to have as many cars as possible in the race.
“Then, the male must have testicles that are as large as possible.”
Prof Bøckman said bonobos have particularly large testicles and mate in large groups whereas gorillas have small testicles.
He said: “There is an abundant flow of semen. Those who leave the greatest amount of sperm have the largest chance of fathering offspring.
“In gorilla troops there is only one male. Even though the gorilla has a small harem, he has no need for large testicles – his balls are tiny.”
Large testicles can increase the risk of testicular cancer, the study found.
“Animals with short lifespans may have enormously large testicles. In one type of grasshopper the testicles occupy half their body mass,” said Prof Bøckman
“The testicles are even larger in sea urchins. They spawn directly into the ocean. To increase the chance of fertilising an egg, the sea urchin is a huge testicle with a little shell around it.”
The testicles of humans are one and a half times larger than those of gorillas.
Prof Bøckman said: “This testifies with abundant clarity to life in our flock. We can pledge our fidelity until we are blue in the face, but this is evidence that our females are cheating.
“We are not like chimpanzees, where the female has four or five sexual partners every time she is in heat, but there is always a certain likelihood that the neighbouring male has dropped by.”
The testicles are also large in animals that have sex with many females.
Prof Bøckman said: “Male lions have huge balls. All the females in the pride must have sex at the same time. When the female lions in the pride are in heat, he must mate with all the females every half-hour for three days.”
Today I’d like to talk about: The Yin and Yang of Desire — Dopamine, Prolactin and Testosterone.
Let’s talk about love, lust and desire. But instead of looking at these things as social phenomena, let’s look at the chemical reactions going on inside our bodies that make us feel and behave the way we do.
There are clear links between certain chemicals and our most basic drives, which explains, for example, why we feel horny one moment and utterly disinterested the next. Or why our sex drive peaks after exercise. At the core of our sexual and affectional interests and behaviors lie the two chemicals — dopamine and prolactin. In many ways they are complimentary to one another; dopamine turns on desire and prolactin turns it off.
Dopamine is a neurotransmitter. This is basically your body’s pleasure and reward system. Our brains releases dopamine, to one degree or another, when we see, read or think about something sexy, taste something sweet, puff a cigarette, or come into skin-to-skin contact with another person. When dopamine levels are high, our libido goes into overdrive. Sometimes levels can be so dramatic that a person will neglect other essential bodily functions like eating and sleeping. Some “street” drugs —meth and coke among them — can mimic the body into thinking it’s dealing with dopamine.
Dopamine is critical to the way the brain controls our movements. If there’s not enough dopamine, we can’t move, or control our movements. If there’s too much dopamine, we are plagued with repetitive moments like jerking, tapping and twitching.
Get this; novel situations can increase dopamine releases. For example, hooking up with someone for the first time triggers especially high levels of dopamine. Curiously enough, these same high levels will not occur again during subsequent hookups with that same person. This is called the one-night-stand phenomenon; it’s why you can be attracted to someone at first encounter but not afterward.
However, falling in love with someone can sustain high dopamine levels for a longer period of time. This explains why physical infatuation is at its peak in the beginning months of a relationship. Also dopamine floods the brain when we get drunk or take certain drugs, which is why drinking alcohol can make a potential partner look more attractive.
Prolactin is dopamine’s foil. It causes dopamine levels to plummet. Prolactin is a hormone, as opposed to a neurotransmitter, like dopamine. It floods the body during orgasm, virtually shutting down the sex drive, which is nature’s way of allowing us to attend to other essential bodily functions like eating and sleeping. Prolactin release in men will temporarily disable our ability to have an erection. This is called the refractory or recovery phase of our sexual response cycle. And prolactin is at least partially responsible for that happy, relaxed state after we cum. This is precisely the release women get while breastfeeding; in fact, the word “pro-lactin” directly indicates its role in milk production.
Prolactin primes the mind for long-term attachment — a role that helps the mother bond with her suckling child as well as lovers to each other. This means that if you stick around cuddling with your partner right after sex, you may actually start to like him/her more and more. This is called the pair-bonding effect. But prolactin’s dopamine-reducing action has a darker side. It cancels the tolerance you may have for your partner’s flaws.
While dopamine and prolactin are good indicators of the immediate workings of sexual pursuit, it is testosterone that best explains long-term changes in courtship. Testosterone is responsible for the masculinization of the adolescent male body during puberty. And it increases the dopamine levels that regulate our sex drive. But testosterone leaves its fingerprint on the body as much as the brain. It’s the catalyst for changes in skin tone, fat distribution, musculature and demeanor, which are signals to others that this individual male is sexually mature and in good health.
However, if you get a fever or become depressed, your testosterone levels can drop significantly. Malnutrition or high levels of anxiety or stress will also interfere with testosterone levels. The most immediate effect of this is a decrease in libido, and a noticeable drop-off in energy levels as well as confidence. There’s no doubt about it; testosterone levels will signal to potential mates that you are in the throws of depression, stress, anxiety or malnutrition. You will appear a little less attractive to people subconsciously. That’s why a confident, dominant male with high-testosterone levels generally enjoy more mating success.
Testosterone levels are highest in the morning, then wanes throughout the day. It’s also much higher in men in autumn and lowest in the spring.
However, sexual desire is still more complicated than is known to science, and there may be multiple archetypes of partners we’re drawn to — there is evidence that aggressive high-testosterone men appear sexier to women and gay men for a one-night stand. But softer, more sensitive balanced men are more likely to tug at our heartstrings in a relationship. Scientists reason that the bulkier mate is more likely to be physically powerful and carry good genes to create strong children. While the slimmer guy is a more loving, reliable partner likely to help raise the kids so they survive to adulthood. The effect of this strange contradiction seems to be a biological predisposition against monogamy and sexual exclusivity.
But none of this is carved in stone. A man’s hormone’s levels increase when he is in a competitive environment or carries out acts of aggression, which can explain how guys seem to bulk up quickly when they go to prison or join sports teams. These levels decrease when he feels intimidated or humiliated, which might explain why those who get picked on at school stay skinny and mild-mannered compared to their peers. This in turn made them easier targets and only increased the likelihood of them being bullied.
This is not uncommon behavior among primate colonies that have huge alpha males looming over a population of smaller, submissive males and females. While this is not a perfect parallel to human social groups, it does go a long way in explaining how a social environment can be a precursor to physical body changes. And just so you know, our testosterone levels also drop during long-term relationships, giving the male brain a sense of stability and mellowness, easing off the drive to forage for new sexual partners.
Science alone lacks a moral element, and fails to explain, in a modern context, why we should desire to be masculine, aggressive, potent or dominant in the first place. In nature, the alpha-male is the most likely to enjoy reproductive success, but that isn’t what gives our lives value today. We might have more success being an average male that falls in love and becomes a good provider. And in the modern world it’s probably the more stable and sensitive man who is most likely to sire children.
Still, science gives important clues to what’s going on in our minds and bodies and that of our potential partners. A lot of our basic inclinations are out of our control, but when we know what causes them or what to expect, we can work with them for the best outcome.
researchers explain in a paper published to the journal 
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