This is an important study from the Psychological Science journal’s early view:
Fetal Testosterone Predicts Sexually Differentiated Childhood
Behavior in Girls and in Boys
Bonnie Auyeung, Simon Baron-Cohen, Emma Ashwin, Rebecca Knickmeyer, Kevin Taylor, Gerald Hackett, and Melissa Hines
ABSTRACT—Mammals, including humans, show sex differences in juvenile play behavior. In rodents and nonhuman primates, these behavioral sex differences result, in part, from sex differences in androgens during early development. Girls exposed to high levels of androgen prenatally, because of the genetic disorder congenital adrenal hyperplasia, show increased male-typical play, suggesting similar hormonal influences on human development, at least in females. Here, we report that fetal testosterone measured from amniotic fluid relates positively to male-typical scores on a standardized questionnaire measure of sextypical play in both boys and girls. These results show, for the first time, a link between fetal testosterone and the development of sex-typical play in children from the general population, and are the first data linking high levels of prenatal testosterone to increased male-typical play behavior in boys.
Here’s the money quote:
Thus, our data are the first documentation that androgen exposure prenatally relates to sexually differentiated play behavior in boys and in girls. In addition, the current results support an organizational, as opposed to current, activational role of testosterone, because play behavior is measured in childhood, when concurrent testosterone levels are low.
Gender non-conformity is the strongest predictor of same-sex attraction in adulthood. This study links prenatal testosterone with later gender typical behavior. The brains of children are organized in ways that react to their environment in socially typical or atypical ways. How such behavior shapes the family environment is unclear, however, it does not appear that the behavior is exclusively a response to parental bonding or modeling.
30 thoughts on “Fetal Testosterone Predicts Sexually Differentiated Childhood Behavior in Girls and in Boys”
I couldn’t have said it better myself. The saddest part is the kids with Autism need help and scientists just blew a few billion dollars and 10+ years time on genes. Anyone with the most basic understanding of science could have told them they wouldn’t find much. No surprise that’s exactly what happened.
Nature has a twin study on Leprosy but I can’t get to it because I don’t have an account. Fortunately somebody posted the basics.
MZ twins show 60% to 85% concordance
DZ twins show 5% to 20% concordance
Leprosy clusters within families. Sib risk ratios reported from 2.9% to 8%
Genome wide scans taken from large multi incidence families have identified a number of candidate leprosy susceptability genes. Leprosy is also a spectrum disorder ranging from mild to severe.
It should be noted that Leprosy is caused by bacteria, not genes.
Usually when we think about causes, we tend to ascribe initiative and direction. If X caused Y, then X initiated and lead to Y. So, if I read your statement on autism being primarily genetic in this key, I conclude that genes are the driver of a disorder that is on the rise. How could autism rate increase if genes are the primary causes? Overdiagnose can be considered, mutations too, but the biggest changes around here, in the last few thousands of years, haven’t been mutations or the quality of medical diagnose, but environment.
I think this idea of genes directly and primarily causing disease has been overinflated, proportionally with the hope that was invested, and money!, in genetics. That is a big change in the environment of medical science practice and research and that can explain a lot more why autism is still thought of as a primarily genetic disorder. It’s because genetics are a major destination for funding research and universities are training more and more geneticists. Every geneticist is biased to exaggerate the influence of genes in disorder or traits.
So, I think we should forget about the primacy of genetics and focus on the interaction between genetics and environmental changes. I can quote geneticists who already stressed that genes are not “for cancer”, “for smoking”, “for gambling” etc, — rather they had a certain function that worked well in an environment they were selected for. But the big and too fast changes in environment were the ones that correlate with an increase in many disorders and diseases that we see today. On this one, I’m with Drowssap, environment must account for why largely the same genes we have with our very distant ancestors produce so many health problems today.
Genes certainly can cause rare variants of any disorder including infertility. For a variety of reasons they can also cause regional disorders that are more common than would otherwise be expected. Of course over time these genes die out too. But I’ve never heard of a common, genetic form of infertility. That’s almost a mathematical impossibility. If you know of one lay it on me. I can see how a relatively new and isolated tribe might have something like this because of Founders Effect but this couldn’t exist in the middle of Europe or Asia unless it’s an amazing exception to the rule.
Generally speaking genetic disorders aren’t more common than about 1 in 10,000. There are a few exceptions but most of these are still 1 in 1000 or fewer. Obviously this refers to young people. The older the age of disease onset the more common a disease gene can be.
The Atlantic Monthly: A New Germ Theory
This is a famous article from 1999 about Dr. Paul Ewald and Dr. Greg Cochran. Much of what was said has now been proven true. Disease always comes back to environmental damage and most of that is pathogens.
Ok, now I’ll leave you alone. 😎
Schizophrenia gene hunters come up empty
Dr. Goldstein got the first part right, natural selection works. His new hypothesis that 1% of the population has Schiz because genes are constantly mutating towards mental illness is laughable. But I guess scientists will say anything to keep their funding alive.
All I’m getting at is that whether it’s Autism, Schiz, Cancer or anything else (especially in children) it almost always comes back to environment. People who claim it’s genes are just waiting around to be proven wrong.
MSNBC: Cancer genes not so cancerous after all
It always works out like this. In this case 238 out of 240 genes turned out to be just fine. That’s a whole lot of “we found the gene that causes cancer” headlines that turned out to be wrong.
Right on! I liked your article, I was only commenting on that one sentence connecting Autism and Genes. I don’t blame you for making that connection because most people (including myself not long ago) believe things like that.
Up until very recently over 90% of all Autism research dollars went towards genetics but that’s changing fast. Like Schizophrenia researchers before them they’ve found nothing more than a few “interesting” corelations. That’s exactly what any highschool biology student would have predicted. Why the NIH spent billions of dollars and over a decade to find out that natural selection works I’ll never know.
Boston Globe: Autism research now aiming at environment
Regarding the discussion of genetics and autism or gender non-conformity versus pathogens, it seems reasonable to think that both factors could be at work for different kids. My view is that we will eventually discover an underlying set of neural conditions that associate with behaviors. Those conditions can be generated in a variety of ways and via a variety of combinations of causes (genetic variability, environmental mischief, and pathogens, etc.)
PS – Nice to have you visit neuroskeptic; feel free to stick around. By the way, Fuel and Creed had a pretty good 1998 as well.
Sorry – I mean P.S Drowsapp
P.S Carole, it would be very easy for a genetic disorder to cause infertility – it would just have to be a recessive trait.
Stuck in 1998 eh? Well I admit, 1998 wasn’t a bad year in music, I mean Garage Inc. is still a great album.
But autism is still generally regarded as a primarily genetic disease. A few people are calling for more money for research on environmental factors, true, but they’re a minority. I mean just do a pubmed search for “autism”: out of the first 20 hits, 8 are directly to do with genetics (1,7,9,10,11,12,13,20)…
Even people who believe in the importance of environmental causes recognise that genetics must play an important part because otherwise everyone who got exposed to certain pollutants would get autism. E.g. some people suggest that there is a genetic vulnerability to mercury poisoning. That’s almost certainly rubbish, but they still believe in genetics.
I think geneticists did such a good multi-decade job of convincing the public that genes cause disease that it will take another decade of germ and pollution discoveries to get the public back on the right track. Even the smartest people including doctors still think that most illness is caused by genes. My wife had a friend who was infertile. Every time she got pregnant she would miscarry the baby. The doctors told her that she had a genetic disorder. How the heck would somebody have a gene that caused infertility? If it existed at all it would be so rare that most doctors would never see a single case.
Wow, Nang Poy definitely looks like a girl in that photo. But every time I’ve seen a transexual on TV it was instantly obvious. I don’t know what gives it away but something about the faces of men and women is different.
About finger lengths and even hair whorls–
From what I have read, neither of these has been substantiated to the point that researchers are in agreement that there has been a sample large enough or a study rigorous enough to make claims and draw conclusions, but I admit I haven’t kept up with the topics.
They got a lot of mainstream press which means nothing.
I took the paragraph in which Neuroskeptic said this to mean he knew of only one gene that so far had shown a relationship to autism.
He says further,
I thought his whole point was that this single word autism was being used to define a whole range of disorders/behaviors.
But you are right in that he sounds as if he is one of those who is under the impression that many different unusual behaviosr must be due to genes.
My introduction to the word autism came in 1972 when a former college roommate who was working as a social worker began working with autistics and their parents. She had to explain the term to me.
The thing is, the way she defined an autistic child hardly compares to the way many articles describe such a child today. So many articles speak of “high-functioning autistics” and how many of them are in the sciences and in math, even teaching in those fields. Believe me, in 1972, such a person was not termed “autistic.”
A term can grow so broad it means little.
Finger length and sexuality
Finger length ratios are an indication of hormone exposure during pregnancy. Lesbians show increased exposure to testosterone as compared to straight women. But gay men with no older brothers have the exact same finger ratios as straight men. When gay men have older brothers it gets more complicated but who knows what that actually means?
I meant Neuroskeptic for writing that we need to find the genes responsible for Autism. Scientists no longer think that Autism is the result of genes or natural processes.
You haven’t seen Nang Poy, a Thai miss who was born a boy with all “the tools” in place. If anything hormonal went gigantically wrong it should have affected the entire body, like it happens in those syndroms. But nope, variations in hormones are bigger between genders than inside genders (ie boys, however typical or not they are, still have a lot more testosterone than girls).
Drowssap, who’s the guy “stuck in 1998?” (I’m confused).
Your other post about autism and the link you provided…yes, I saw that. Good one.
As for autism–gender atypical play has been reported to be higher in autistics than in the general population, right?
Evan, as for your link…progesterone, huh? Hadn’t heard that one.
Wow. I get the feeling these researchers have data and no real idea of how to interpret it. I get the feeling some other factors are at play (no pun intended).
It’s also very hard to find a cause of autism when each researcher seems to have a different definition of what does and what doesn’t comprise autism.
“It’s time to start looking for the environmental culprits responsible for the remarkable increase in the rate of autism in California”
Awesome Autism article! But the guy (like most people) is still stuck in 1998.
Autism isn’t caused by genes or other natural processes. All of the funding is switching to environment. It’s either pathogens or pollution.
My boss at my old job was a classic example of this. He had an oddly short pointer finger, square jaw and was an ex-marine. He looked like a classic tough guy. No doubt he was exposed to extra testosterone in the womb.
But here is the thing. It’s true that on average gay men are more feminine than straight men. However many gay and transgendered men are significantly more feminine than women or girls.
I don’t think I’ve ever met a girl as feminine as Chris Crocker.
Leave Britney Alone
If he received less testosterone in the womb than a girl shouldn’t he have physical anomolies? Shouldn’t feminine gay men have known physical differences? Maybe they would tend to have undecended testicles and things like that.
The other thing is that they’ve tested hormones to death on sheep and they haven’t been able to do much besides change stereotypical sheep behavior. But they are still gay and straight.
LOL!!! Carole, I had bloodwork this morning and wasn’t allowed my usual caffeine fix either!! Can’t hink for crap!
I’ve got one comment waiting for moderation.
underline, code, italic, bold,
I thought this link helpful as well. It seems as if this research team used the same strategy to establish a link between fetal testosterone and autism that they used to establish a link between fetal T. and gender atypical play–amniotic fluid measures and a questionnaire filled out by parents.
I don’t know what to think except that their conclusions have plenty of detractors (not that that means anything!). I’m simply supplying this link for those who’d like to read another article about their research.
The link between T exposure and play behaviour (and toy preference) in genders has been investigated and documented many times before. I quoted this study just last year on the Throckmorton blog:
But there are many others. Cohen-Bendahan et al (2004) have reviewed a literature of close to 300 scientific papers on this subject. Many more have been published since then.
Their claim is very bold in scientific jargon and must be qualified. In this field of psychoneuroendocrinology the devil hides in the details. Not much to say until we see the study, methods, sample, etc. Simon Baron-Cohen, who is known for his contributions in the field of autism and amygdala studies, must know what they’re claiming primacy for.
Well, duh–why didn’t I just give the link? Because I haven’t yet had enough coffee this morning, I guess.
I should have added to my previous post that the link to the helpful critique about which I sploke is under the comments section–there is a comment from Neuroskeptic and a link to his blog. I think it’s well worth reading.
Warren, I admit to being cheap–I didn’t purchase the article so all I read was the provided abstract.
However, I did type in “fetal testosterone” and first up came a link to a summary of this same research team’s work examining their hypothesis that there may be a link between fetal testosterone and autism. In this summary is a very helpful link to a person whose blog I am familiar with–neuroskeptic. He offers interesting commentary and a critique on the team’s work involving testosterone and autism.
I’ll let everyone else decide what they think but the link and his comments are worth following and one wonders if the same critique can be applied to their findings on fetal testosterone and differential childhood behavior.
I never knew, but realize now that I should have, that amniosentesis tests for research weren’t allowed. Is that so in the USA as well?
LOL!!!! It does if a parent does not want their daughter playing with trucks and a disturbance arises out of this. Doesn’t it?
Sort of like, if a parent sees “problem” then they make a problem. That’s a problem.
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