̽��ֱ�� of Cambridge - testosterone

‘Believing you’re a winner’ gives men a testosterone boost and promiscuous disposition

fpjl2 — Thu, 09 Aug 2018 08:36:05 +0000

A new study shows that men only have to believe they’ve bested another man in competition to get raised testosterone levels and an inflated sense of their own value as a sexual prospect.

Scientists found that this hormonal and psychological shift made men more inclined to approach new potential partners.

̽��ֱ��research team measured hormone levels, as well as self-perceived attractiveness and confidence in approaching women, in 38 men in their twenties before and after competing in head-to-head battles on rowing machines.

Unbeknownst to participants, the competitions in the study were rigged to randomly declare the winner, regardless of who was the stronger rower.

While previous studies have shown that winning can affect male hormones, it was not known whether this was down to the efforts it takes to win or the belief that one is victorious.

̽��ֱ��latest study, led by biological anthropologists from the ̽��ֱ�� of Cambridge and published today in the journal Human Nature, reveals that just being convinced you have won, or indeed lost, is enough to cause male hormonal fluctuations that can influence sexual behaviour.

Researchers say this is an example of “plasticity”: the body adapting quickly – without altering genetic make-up – to suit a change in circumstance. In this case a perceived change in social status, due to the men believing they have defeated a rival.

̽��ֱ��body attempts to take advantage of this apparent status improvement by inducing chemical and consequently behavioural changes that promote a “short-term” approach to reproductive success, say the researchers. Namely, more sex with new and different partners.

“Much of evolution consists of trade-offs in energy investment,” said study lead author Dr Danny Longman, from Cambridge’s Department of Archaeology.

“A common trade-off for males both across and within species is between mating strategies. One reproductive approach is short-term, investing time and energy in attracting and pursuing many mates, and fighting off competition. Another approach is long-term, investing energy in raising offspring with a single mate.”

“We found that a perceived shift in social status can cause male physiology to adapt by preparing to shift mating strategies to optimise reproductive success.”

Longman points out that in many animal populations, male social hierarchies correspond with reproductive success, and social status is determined by competition between males.

̽��ֱ��study used a simple proxy for social and sexual competition by pitting athletic young men against each other to see who was the most powerful rower.

“Victory in a rowing contest strongly implies the possession of greater physical strength than the opponent, a trait found to be valued by women in our evolutionary past when choosing a mate,” said Longman.

He took saliva samples to test hormone levels before and after the races. A number of psychological questionnaires were also administered, designed to gauge self-esteem, ‘sociosexuality’ (willingness to engage in casual sex), ‘self-perceived mate value’ and mating behaviour (e.g. the likelihood of approaching attractive women). Crucially, Longman and colleagues then manipulated the results of the races.

̽��ֱ��men who believed they had won received an average testosterone increase of 4.92%, while those convinced they had lost dropped by an average of 7.24%. Overall, men who thought they were winners had testosterone levels 14.46% higher their deflated opponents.

̽��ֱ��men who thought they had lost showed no difference in their perceived value as a mate or confidence approaching women. However, the men who felt like winners had a ‘self-perceived mate value’ that was 6.53% higher, on average, than their rivals, and were 11.29% more likely to approach attractive women in an effort to instigate sexual relations.

“ ̽��ֱ��endocrine system that controls hormones is responsive to situational changes. Previous research has shown that testosterone is lower when men are in a committed relationship, or have children, to promote long-term mating strategies,” said Longman.

“Our results show that both testosterone and its corresponding psychological effects can fluctuate quickly and opportunistically, shifting towards short-term mating in response to a perceived change in status that may increase mating value.”

Male social status has less to do with physical strength in many modern societies, and Longman would be curious to see if similar results arise from intellectual challenges more familiar to the office-based culture many men now inhabit. There is always the issue of free will, however.

“Male physiology may shift to take advantage of certain situations, but ultimately a man’s decisions are up to him.”

New findings suggest that the male body tries to “optimise” self-perceived improvements in social status through hormonal shifts that promote “short-term mating”.

Our results show that both testosterone and its corresponding psychological effects can fluctuate quickly and opportunistically

Danny Longman

U.S. Army

U.S. Army World Class Athlete Program wrestler Spc. Jeremiah Davis (right) squares off against Sunkist Kids' Joe Betterman

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Women with polycystic ovary syndrome more likely to have a child with autism

cjb250 — Wed, 01 Aug 2018 12:00:44 +0000

PCOS affects about one in ten women and is caused by elevated levels of the hormone testosterone. It is associated with fluid-filled sacs (called follicles) in the ovaries, and with symptoms such as delayed onset of puberty, irregular menstrual cycles, and excess bodily hair.

Autism is a condition characterized by difficulties in social interaction and communication alongside unusually narrow interests, a strong preference for predictability, and difficulties adjusting to unexpected change. Some autistic people also have learning difficulties and delayed language, and many have sensory hyper-sensitivity. ̽��ֱ��signs of autism are evident in childhood even if the diagnosis is not made until later, and occurs in about 1% of the population.

̽��ֱ��research team previously published work in 2015 which showed that before they are born, autistic children have elevated levels of ‘sex steroid’ hormones (including testosterone) which ‘masculinise’ the baby’s body and brain. ̽��ֱ��discovery that prenatal sex steroid hormones are involved in the development of autism is one possible explanation for why autism is diagnosed more often in boys.

̽��ֱ��scientists wondered where these elevated sex steroid hormones were coming from, one possible source being the mother. If she had higher levels of testosterone than usual, as is the case in women with PCOS, then some of the hormone might cross the placenta during pregnancy, exposing her unborn baby to more of this hormone, and changing the baby’s brain development.

Using anonymous data from a large database of GP health records, the study looked at 8,588 women with PCOS and their first-born children, compared to a group of 41,127 women without PCOS. ̽��ֱ��team found that, even after taking into account other factors (like maternal mental health problems or complications during pregnancy), women with PCOS had a 2.3% chance of having an autistic child, compared with the 1.7% chance for mothers without PCOS.

̽��ֱ��team stressed that the likelihood of having an autistic child is still very low, even among women with PCOS – but finding this link provides an important clue in understanding one of the multiple causal factors in autism.

̽��ֱ��team presented their findings at the International Meeting for Autism Research in 2016, and their findings were replicated in a Swedish study in the same year, adding to the reliability of the result.

̽��ֱ��team also conducted two other studies using the same data and found that autistic women were more likely to have PCOS, and women with PCOS were more likely to have autism themselves. This strongly suggests that these two conditions are linked, probably because they both share elevated sex steroid hormone levels.

Adriana Cherskov, the Master’s student who analysed the data, and who is now studying medicine in the US, said: “This is an important piece of new evidence for the theory that autism is not only caused by genes but also by prenatal sex steroid hormones such as testosterone.”

Professor Simon Baron-Cohen, Director of the Autism Research Centre, who supervised the research, said: “This new research is helping us understand the effects of testosterone on the developing fetal brain, and on the child’s later behaviour and mind. These hormonal effects are not necessarily independent of genetic factors, as a mother or her baby may have higher levels of the hormone for genetic reasons, and testosterone can affect how genes function.”

Dr Carrie Allison who co-supervised the research, said: “We need to think about the practical steps we can put in place to support women with PCOS as they go through their pregnancies. ̽��ֱ��likelihood is statistically significant but nevertheless still small, in that most women with PCOS won’t have a child with autism, but we want to be transparent with this new information.”

Dr Rupert Payne from the ̽��ֱ�� of Bristol Centre for Academic Primary Care, a GP and the expert on the team in using GP health record data for this type of research, said: “Autism can have a significant impact on a person’s wellbeing, and on their parents, and many autistic people have significant health, social care and educational special needs. This is an important step in trying to understand what causes autism. It is also an excellent example of the value of using anonymous routine healthcare data to answer vital medical research questions.”

̽��ֱ��study was supported by the Autism Research Trust, the Medical Research Council, Wellcome, a Gates Cambridge Trust Scholarship and Rouse Ball/Eddington Research Fund Award at Trinity College.

Reference
Cherskov, A., Pohl, A Allison, C, Zhang, H, Payne, R, and Baron-Cohen, S. Polycystic ovary syndrome and autism: A test of the prenatal sex steroid theory. Translational Psychiatry; 1 Aug 2018; DOI: 10.1038/s41398-018-0186-7

Women with polycystic ovary syndrome (PCOS) are more likely than other women to have an autistic child, according to an analysis of NHS data carried out by a team at Cambridge ̽��ֱ��’s Autism Research Centre. ̽��ֱ��research is published today in the journal Translational Psychiatry.

This is an important piece of new evidence for the theory that autism is not only caused by genes but also by prenatal sex steroid hormones such as testosterone

Adriana Cherskov

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Winner takes all: Success enhances taste for luxury goods, study suggests

sc604 — Tue, 19 Sep 2017 14:52:15 +0000

While we may sometimes make expensive purchases because of the high quality of a product, these items often represent status symbols, a phenomenon termed ‘conspicuous consumption’. Evolutionary psychologists claim that conspicuous consumption may be comparable to ostentatious behaviours or elaborate physical characteristics seen in the animal kingdom. A peacock’s tail may be energetically costly to build, but may serve as an indicator of genetic quality; similarly, conspicuous consumption may represent a costly display of wealth that serves to increase an individual’s social status.

Previous studies have suggested that testosterone plays a key role in human social status seeking, with elevated levels of the hormone being associated with more dominant and aggressive behaviour in men. It has also been suggested that testosterone levels increase in response to an individual winning a competition, and fall in response to losing.

In a study published today in the journal Scientific Reports, Yin Wu, at the time a PhD student at the ̽��ֱ�� of Cambridge, in collaboration with researchers from London Business School, ̽��ֱ�� of Oxford, and ̽��ֱ�� of Vienna, led an investigation into the effects of social status and testosterone levels on conspicuous consumption. Dr Wu tested the effects of winning or losing a competitive version of the game Tetris on the behaviour and testosterone levels of 166 male volunteers – although in fact, while the participants thought they were competing against each other in two-player games, they were randomly assigned as winners or losers.

After playing the Tetris game, the researchers asked the participants how much they would be willing to pay for luxury items such as expensive cars, from 10% of its retail price up to 120%. They found that winners tended to be willing to pay more for these items than losers. This effect was confirmed with some status products made in the laboratory, such that winners were more willing than losers to pay for a Harvard ̽��ֱ�� T-shirt.

Next, participants were asked to attribute positive and negative words to the items. This task helps assess the implicit value that participants assigned to the objects – in experiments, this is used to measure attitudes that people are unwilling to reveal publicly, and in the field of consumer psychology, these measures can predict brand preferences, usage, and recognition. ̽��ֱ��current study supported the finding that winners attach greater value than losers to luxury items.

Finally, the researchers measured the participants’ testosterone levels. Contrary to expectations, winning and losing had no observable effect on testosterone levels. This suggests that testosterone does not play a role in conspicuous consumption.

“Winning a competition, which we know is associated with feeling a sense of a higher social status, seems to drive individuals towards conspicuous consumption, making them more willing to pay for luxury items,” says Dr Wu, now based at Shenzhen ̽��ֱ�� in China. “However, we were surprised that testosterone levels did not change with winning or losing, and so testosterone does not seem to be driving the effects on conspicuous consumption.”

̽��ֱ��researchers argue that one way in which winning leads to conspicuous consumption is through an enhanced sense of entitlement among winners, the feeling that as winners they are more deserving of preferential treatment than others: the Tetris ‘winners’ may have felt more deserving of the high-status products and also of fair treatment in the ultimatum game. This would be consistent with findings that feelings of superiority over others arising from hard work and success enhance the desire to purchase luxury brands, as individuals see the luxury goods as a reward.

“We are not only interested in examining what people are willing to do to win, but also in understanding the consequences of winning on people’s everyday behaviour,” says Dr Amos Schurr, a behavioural economist at Ben-Gurion ̽��ֱ�� of the Negev, Israel, who was not part of this study.

“Social competition is pervasive in our daily life – whether it is in terms of fighting for the top job, competing for friends and popularity or even growing up in a wealthy, successful family,” says Dr Wu. “Our study demonstrates that winning a competition leads people to prefer high-status products, possibly through an increased feeling of entitlement or deservingness.”

Concerning the null findings on the testosterone levels, the researchers suggested that competition-induced testosterone fluctuations may be hard to detect, and so they are carrying out further work to test the effects of testosterone on conspicuous consumption in their on-going project.

This study was conducted at the ̽��ֱ�� of Cambridge’s Behavioural and Clinical Neuroscience Institute, funded by Medical Research Council and Wellcome Trust.

Reference
Wu, Y et al. ̽��ֱ��role of social status and testosterone in human conspicuous consumption. Scientific Reports; 18 September 2017; DOI: 10.1038/s41598-017-12260-3

Footballers in flashy cars, City workers in Armani suits, reality TV celebrities sipping expensive champagne while sitting in hot tubs: what drives people to purchase luxury goods? New research suggests that it may be a sense of being a ‘winner’ – but that contrary to expectations, it is not driven by testosterone.

Social competition is pervasive in our daily life – whether it is in terms of fighting for the top job, competing for friends and popularity or even growing up in a wealthy, successful family.

Yin Wu

David Villarreal Fernández

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Distance running may be an evolutionary ‘signal’ for desirable male genes

fpjl2 — Wed, 08 Apr 2015 18:05:25 +0000

Pre-birth exposure to high levels of the male sex hormone testosterone has already been shown to confer evolutionary advantages for men: strength of sex drive, sperm count, cardiovascular efficiency and spatial awareness, for example.

Now, latest research on marathon runners using finger length as a marker for hormone exposure shows that people who experienced higher testosterone in the womb are also better at distance running – a correlation particularly strong in men, although also present in women.

Researchers say the finding that males with greater “reproductive potential” from an evolutionary standpoint are better distance runners suggests females may have selected for such athletic endurance when mating during our hunter-gatherer past, perhaps because ‘persistence hunting’ – exhausting prey by tirelessly tracking it – was a vital way to get food.

Distance running may also have acted as a positive ‘signal’ for females of desirable male genetics more generally, say researchers: good runners were likely to be better persistence hunters and consequently better providers. This increases the likelihood they would have other key traits of good providers such as intelligence and generosity.

̽��ֱ��study was conducted by researchers at the ̽��ֱ�� of Cambridge’s Division of Biological Anthropology and is published today in the journal PLOS ONE.

“ ̽��ֱ��observation that endurance running ability is connected to reproductive potential in men suggests that women in our hunter-gatherer past were able to observe running as a signal for a good breeding partner,” said the study’s lead author Dr Danny Longman.

“It was thought that a better hunter would have got more meat, and had a healthier – and larger – family as a consequence of providing more meat for his family. But hunter-gatherers may have used egalitarian systems with equal meat distribution as we see in remaining tribes today. In which case more meat is not a factor, but the ability to get meat would signal underlying traits of athletic endurance, as well as intelligence – to track and outwit prey – and generosity – to contribute to tribal society. All traits you want passed on to your children,” he said.

Using the largest sample of marathon runners of any study of its kind, Longman and colleagues tested for specific finger lengths known as the 2D:4D digit ratio. Previous studies have showed that those exposed to more prenatal testosterone have a longer ring finger (4th digit) in comparison to their index finger (2nd digit).

This digit ratio is the most accurate known way to tell if an adult was exposed to higher levels of testosterone as a foetus – a proven predictor of the “potential for reproductive success” in men, say researchers.

̽��ֱ��team analysed 542 runners (439 men; 103 women) at the Robin Hood half marathon in Nottingham by photocopying hands and taking run times and other key details just after runners crossed the line.

They found that the 10% of men with the most masculine digit ratios were, on average, 24 minutes and 33 seconds faster than the 10% of men with the least masculine digit ratios.

̽��ֱ��correlation was also found in women, but was much more pronounced in men, suggesting a stronger evolutionary selection in men for running ability. ̽��ֱ��10% of women with the most masculine digit ratios were, on average, 11 minutes and 59 seconds faster than the 10% with the least masculine.

Longman points out that prenatal testosterone exposure is a very small influence on running ability that doesn’t compete with training and muscle strength when it comes to performance, but their unprecedentedly large sample size of over 500 people enabled the team to gather conclusive evidence.

“Humans are hopeless sprinters. Rabbits, for example, are much faster sprinters, despite being fat and round. But humans are fantastically efficient long-distance runners, comparable to wolves and wild coyotes,” said Longman.

“We sweat when most animals would overheat; our tendons and posture are designed to propel our next strides – there was likely a selective pressure for all these benefits during our evolution.”

Persistence hunting is thought to have been one of the earliest forms of human hunting, evolving approximately two million years ago, said Longman.

“You can still see examples of persistence hunting in parts of Africa and Mexico today. Hunters will deliberately choose the hottest time of day to hunt, and chase and track an antelope or gnu over 30 to 40 kilometres for four or five hours. ̽��ֱ��animal recovers less and less from its running until it collapses exhausted and is easy to kill,” Longman said.

“This may sound crazy, but when a hunter is relatively fit the amount of energy they expend is actually tiny compared to the energy benefits of an antelope-sized animal, for example. Before the domestication of dogs, persistence hunting may have been one of the most efficient forms of hunting, and as a consequence may have shaped human evolution.”

New research shows that males with higher ‘reproductive potential’ are better distance runners. This may have been used by females as a reliable signal of high male genetic quality during our hunter-gatherer past, as good runners are more likely to have other traits of good hunters and providers, such as intelligence and generosity.

Persistence hunting may have been one of the most efficient forms of hunting, and as a consequence may have shaped human evolution

Danny Longman

Warein

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Extra testosterone reduces your empathy

ns480 — Thu, 10 Feb 2011 15:45:37 +0000

In addition, the effects of testosterone administration are predicted by a fetal marker of prenatal testosterone, the 2D:4D ratio. ̽��ֱ��study has important implications for the androgen theory of autism (testosterone is an androgen) and confirms earlier rodent research that shows that testosterone organizes very early brain development in a way that affects activity of the hormone in later life.

Professor Jack van Honk at the ̽��ֱ�� of Utrecht and Professor Simon Baron-Cohen at the ̽��ֱ�� of Cambridge designed the study that was conducted in Utrecht. They used the 'Reading the Mind in the Eyes' task as the test of mind reading, which tests how well someone can infer what a person is thinking or feeling from photographs of facial expressions from around the eyes.

Mind reading is one aspect of empathy, a skill that shows significant sex differences in favour of females. They tested 16 young women from the general population, since women on average have lower levels of testosterone than men. ̽��ֱ��decision to test just females was to maximize the possibility of seeing a reduction in their levels of empathy.

̽��ֱ��researchers not only found that administration of testosterone leads to a significant reduction in mind reading, but that this effect is powerfully predicted by the 2D:4D digit ratio, a marker of prenatal testosterone. Those people with the most masculinized 2D:4D ratios showed the most pronounced reduction in the ability to mind read.

Jack van Honk said: "We are excited by this finding because it suggests testosterone levels prenatally prime later testosterone effects on the mind."

Simon Baron-Cohen commented: "This study contributes to our knowledge of how small hormonal differences can have far-reaching effects on empathy."

̽��ֱ��new study has several important implications. First, that current levels of testosterone directly affect the ability to read someone else's mind. This may help explain why on average women perform better on such tests than men, since men on average produce more testosterone than women.

Second, that the digit ratio (2D:4D), a marker of fetal testosterone, predicts the extent to which later testosterone has this effect. This suggests testosterone levels in the womb have an 'organizing' or long-range effect on later brain function. Finally, given that people with autism have difficulties in mind reading, and that autism affects males more often than females, the study provides further support for the androgen theory of autism.

A new study from Utrecht and Cambridge Universities has for the first time found that an administration of testosterone under the tongue in volunteers negatively affects a person’s ability to ‘mind read’, an indication of empathy. ̽��ֱ��findings are published this week in the journal Proceeding of the National Academy of Sciences.

This study contributes to our knowledge of how small hormonal differences can have far-reaching effects on empathy.

Professor Simon Baron-Cohen

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Amniocentesis: a key to identify autism in the womb?

bjb42 — Tue, 04 Jan 2011 16:14:19 +0000

̽��ֱ��new research is based on a study that the Autism Research Centre lab has been engaged in for the last 10 years. That was when the lab started collecting the samples of amniotic fluid that are taken routinely in about six per cent of pregnancies. Usually these samples are analysed for chromosomal abnormalities that might predict the unborn child to be at risk for conditions such as Down Syndrome. After the cytogenetics lab has tested for such chromosomal abnormalities, the fluid is stored for up to a year before being disposed of. Researchers have taken the novel step of asking the biochemists at Addenbrooke’s Hospital to test these samples for the amount of the ‘male hormone’, testosterone.

Of course, testosterone is not just a male hormone, as both sexes produce it. Male foetuses produce twice as much as females, and it is of interest because animal research suggests it is foetal testosterone (FT) that has an organising effect on brain development. It is well recognised that the average male brain differs from the average female brain, not just in overall size (males having the bigger brain) but in the size of specific structures in the brain. In the average female brain, structures like the corpus callosum (the connective tissue between the two hemispheres) is thicker, whilst in the average male brain, structures like the amgydala (the almond-shaped brain region deep beneath the cortex, sometimes thought of as the emotion centre) is bigger.

Testosterone is produced in males by the testes, and in females by the adrenal glands, and then is taken up in the blood to the brain. It crosses the blood-brain barrier and binds to Androgen Receptors. ̽��ֱ��regions of the brain that differ between the sexes also differ in the number of Androgen Receptors. ̽��ֱ��Androgen Receptors, bound with testosterone, affect neural connectivity in different ways.

̽��ֱ��significant issue is that even within one sex, there is substantial variation in how much FT is produced. Some girls produce as much as boys in the typical male range, and some boys produce as little as girls in the typical female range. ̽��ֱ��question the research has been testing is: does your FT level before you are born predict anything about your later psychological development?

̽��ֱ��answer is clear: yes it does. FT levels are negatively correlated with the amount of eye-contact the child makes at 12 months, how fast the child is developing language at 18 and 24 months, and social skills at 48 months of age. These results are found not just when boys and girls are combined, but also when just boys are studied. FT levels are also positively correlated with ‘narrow interests’ at 48 months old. ̽��ֱ��research findings have recently been summarized in a monograph by the team (Prenatal Testosterone in Mind, MIT Press, 2005).

These studies have so far only followed children who are developing normally, but show that individual differences in sociability, language development, and narrow interests (even within the general population) are influenced to some extent by prenatal hormones. ̽��ֱ��lab is going on to test much larger samples (thousands, instead of hundreds) in order to see if children with a formal diagnosis of autism or Asperger’s syndrome had higher FT levels in the womb. Larger samples are needed because autism only occurs in about one per cent of children.

̽��ֱ��relevance of this study of FT to autism is two-fold. First, it might reveal an important cause of autism, opening the door to further basic biomedical research investigating genetic factors influencing FT. Related to this, it might help explain why autism is far more common among males. Second, a prenatal test could enable intervention to begin at birth, rather than waiting for years by which time valuable opportunities for special education or other kinds of learning may have been missed. ̽��ֱ��researchers are clear that they are not undertaking this kind of research in order to lead to termination of the pregnancy, simply because autism exists on a spectrum of severity, and at the milder end of the spectrum the condition is often associated with unusual talents: for example, the narrow interests might be channelled into fields such as mathematics or music, not just social or communication disability.

www.autismresearchcentre.com/arc/default.asp

Cambridge researchers are pioneering a new test for autism in the womb, by measuring the levels of testosterone produced by the foetus, which makes its way into the amniotic fluid. They hope to test if children who later develop autism have unusually high levels of testosterone between 12 and 20 weeks of pregnancy.

...it might help explain why autism is far more common among males.

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Research links testosterone levels to autistic traits

bjb42 — Tue, 13 Jan 2009 00:00:00 +0000

̽��ֱ��findings, published in yesterday's British Journal of Psychology (January 12), show that levels of testosterone in amniotic fluid were linked to children's autistic traits up to ten years later.

Dr Bonnie Auyeung, Professor Simon Baron-Cohen and their colleagues at the ARC measured the levels of foetal testosterone in the amniotic fluid of 235 women who underwent amniocentesis (a test of the amniotic fluid to determine genetic defects in the foetal DNA) during pregnancy. Years later these mothers completed questionnaires that measured their child's autistic traits. By this time, the 118 boys and 117 girls were aged between 6 and 10.

High levels of foetal testosterone were found to be associated with high scores on two separate measures of autistic traits (the Child Autism Spectrum Quotient (AQ-Child) and the Childhood Autistic Spectrum Test (CAST)) for both boys and girls. High scores on these measures of autistic traits reflected poorer social skills and imagination but good attention to, and memory for detail.

Professor Baron-Cohen said: " ̽��ֱ��study highlights for the first time the association between foetal testosterone and autistic traits. We all have some autistic traits - these are a spectrum or a dimension of individual differences, like height."

He added: "It is a shame that this research was inaccurately reported in some sections of the media that suggested the study demonstrated that elevated foetal testosterone is associated with a clinical diagnosis of autism or Asperger Syndrome. Our study has not yet shown that. To do that would need a sample size of thousands, not hundreds. Our ongoing collaboration with the Biobank in Denmark will enable us to test that link in the future.

"Reports also linked this research with prenatal screening for autism that was not the objective of this study. This study was not a screening study and was conducted purely to understand the basic neurobiological mechanisms underlying individual differences in autistic traits."

Dr Auyeung commented: "This research goes further than previous studies which have found that higher levels of foetal testosterone are associated with less eye contact in the child's first year, slower language development by their second birthday, more peer difficulties at four years old and more difficulties with empathy by the time they're six. This new study also links higher foetal testosterone to autistic traits such as excellent attention to detail, and a love of repetition, as well as social and communication difficulties".

This unique longitudinal project was funded by the Medical Research Council and the Boston-based Nancy Lurie Marks Family Foundation. ̽��ֱ��published paper as a pdf is available from the Autism Research Centre's website, follow the link on the right.

Research at Cambridge ̽��ֱ��'s Autism Research Centre (ARC) has found that exposure to high levels of testosterone in the womb is related to the development of autistic traits.

We all have some autistic traits - these are a spectrum or a dimension of individual differences, like height.

Professor Baron-Cohen

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