September 11, 2011
Higher Fetal Androgens Alter Female Brain Development

The rare genetic condition congenital adrenal hyperplasia (CAH) boosts androgen hormone exposure in the womb. Women with CAH have stronger interest in science, technology, engineering and mathematics (STEM) careers than women who have normal hormone levels. CAH does not appear to influence male career interests.

Teacher, pilot, nurse or engineer? Sex hormones strongly influence people's interests, which affect the kinds of occupations they choose, according to psychologists.

"Our results provide strong support for hormonal influences on interest in occupations characterized by working with things versus people," said Adriene M. Beltz, graduate student in psychology, working with Sheri A. Berenbaum, professor of psychology and pediatrics, Penn State.

Berenbaum and her team looked at people's interest in occupations that exhibit sex differences in the general population and are relevant to science, technology, engineering and mathematics (STEM) careers. The researchers studied teenagers and young adults with congenital adrenal hyperplasia -- a genetic condition -- and their siblings who do not have CAH.

This shouldn't be too surprising. Sex hormones alter brain development. But it reminds me of an interesting question: When the capability to intentionally alter fetal hormonal environment becomes pretty refined and powerful what will people do with this capability?

There's a legal angle to this: Suppose prospective parents 10 or 20 years from now decide to alter the womb environment in a female pregnancy in order to temporarily induce the conditions that CAH causes. Suppose they'll be able to do this without a doctor's help. Will prosecutors try to bring charges against them? If so, for what?

Imagine instead that prospective parents decide to reduce the level of hormones for a male fetus in order to create a feminized son. Again, legal grounds for charges to be brought? Should it be illegal to substantially alter the degree of masculine or feminine qualities developed in a fetus?

Do you believe parents should be free to create combinations of cognitive attributes that are currently quite rare? Is that cruelty to their future child and future adult? Consider that some combinations of attributes would be very hard to live with. Someone so altered might not be able to, for example, find someone to form a romance with who would have compatible desires.

Share |      Randall Parker, 2011 September 11 09:42 PM  Brain Sex Differences


Comments
Mthson said at September 12, 2011 2:40 AM:

Maybe abnormal phenotypes will nonetheless become more rare overall if parents are screening out the abnormalities that occur in 'wild-type' humans, like micropenis, so even without regulation it'd be a net benefit.

penny said at September 12, 2011 4:26 AM:

More of this tired nonsense. This was reported decades ago.

You might check out female student levels in engineering.

There are many first rate research female mathematicians who are feminine, normal women.
Spacial and mathematical gender differences vanish and even reverse in cultures like the nordic countries, where females
are treated more equally.

This year's international math Olympiad Gold medalist--with more points over several years than anyone in history-- is
a feminine girl.

Penny

Former member of the Princeton Institute for Advanced Study, and the Max Planck Institute for Math, whose Phd advisor was
a woman. And my advisor was very feminine---an actress before a career change--also a former Princeton Institute member-- and, at that time, a world class expert in transonic fluid dynamics.

I am differential geometer and mathematical physicist---who was a very feminine girl that played with dolls, was NOT
a tomboy, and loved astronomy, which has a long female research tradition.

bbartlog said at September 12, 2011 7:20 AM:

I think regulation of prenatal modifications such as these would be called for. Some traits are obnoxious socially even if advantageous to those that have them (e.g. the so-called dark triad personality traits). In other cases there could be a destructive arms race of some sort (say, in male height).

@penny: do you disagree with the conclusions of the linked-to research? Even if you disagree with the specifics in re CAH, are you further claiming that prenatal influence of the kind described is impossible? As for the 'tired nonsense' (by which I assume you mean the assertion of sex-linked differences in aptitude and interest in math or more broadly STEM): Most of what you've offered is a set of individual exceptions, which are interesting but would only be relevant if someone were arguing that it is *impossible* for women to be good at math.
As for female students in engineering, I assume you are talking about stuff like this: http://www.sdstate.edu/news/featurestories/growing-female-enrollment.cfm, or this: http://engineering.colorado.edu/overview/enrollment3.htm . Funny articles, all about percentage increases and total numbers of female students, which assiduously avoid any mention of total male engineering enrollment. How to lie with statistics, badly.
Anyway - not too surprising that there are far more female engineering students (compared to previous levels) given that women have become a majority of college students overall. But they are still a minority in engineering overall.
As for the nordic countries, I would be interested in seeing the research. But I see that you bring the same bias to the table as Jared Diamond (in Guns, Germs and Steel, albeit wrt human intelligence differences): 'gender differences vanish and *even reverse*'... willing to entertain the notion of a natural advantage to some group, as long as it's the politically correct one.

Bruce said at September 12, 2011 9:38 AM:

This is awfully sexist:

""We found there is a biological influence on that interest toward things, so maybe women aren't going into STEM careers because what they're interested in -- people -- isn't consistent with an interest in STEM careers," said Beltz. "Maybe we could show females ways in which an interest in people is compatible with STEM careers.""


It suggests women should be steered into certain careers because those careers are perceived as being "male dominated" and better.

Maybe the women designing these programs should just stop hating men and if men dominate, let them be and quit stealing money from those programs to entice uninterested women.

Phillep Harding said at September 12, 2011 9:40 AM:

@Penny, a closer examination of exactly what different cultures consider "rape" might be rather startling. Just as a beginning point.

However, I see nothing to indicate that a talent for math is un-feminine. (I note a lack of lesbian superiority movement members, I mean, "fem libbers", in math and hard sciences.) I read the author as saying, if this sort of hormone manipulation, then what about other types of hormone manipulation?

bmack500 said at September 12, 2011 9:59 AM:

This makes me wonder -

Could male fetal exposure to BPA and other estrogen - like substances possibly produce a homosexual child? Might be worth looking into.

FYI, This is not a knock against gay people - I personally don't care about someone's sexual orientation (except, of course, my wife!).

Richard Aubrey said at September 12, 2011 11:57 AM:

Could be a conundrum for the pro-choice people. If an in utero marker for homosexuality were found, and if were possible to use some hormone treatment to make the kid hetero, would the pro-choice or gay communities object? And if so, on what grounds?
We already know that abortion for sex selection is allowed, doctrinally, by pro-choice folks, notwithstanding feminism.

Jay Manifold said at September 12, 2011 11:57 AM:
Do you believe parents should be free to create combinations of cognitive attributes that are currently quite rare?

I view this as an extension of what parents already do – choose one another, and thereby choose their children’s attributes. See A Farewell to Alms for possible evidence of significant societal effects of ~15 generations of relative reproductive success by the more affluent, who could literally afford to be picky. Time preference and violence decrease; literacy, numeracy, thrift, and time-on-task increase.

My answer would therefore be “yes.”

Tcobb said at September 12, 2011 1:30 PM:

One might like to examine the "one child" policy of China to see where this kind of thing can turn sour. A generation is growing up with a huge imbalance in the ratio of males to females.

And what will happen if the government decides in the future that it will be mandatory to adjust the hormones in the womb to produce a "better" crop of citizens? Better for whom, and for why?

I see no good coming of this at all.

Hucbald said at September 12, 2011 2:43 PM:

@penny

Yours is the tired nonsense. At the extreme right edge of the intelligence bell curve, there are NO WOMEN AT ALL.

There has never been a female Da Vinci, Michelangelo, or Rembrandt. There has never been a female Newton, Einstein, or Hawking. There has never been a female Bach, Mozart, or Beethoven. This isn't because females have been kept down by males, it is because at the highest levels of intellectual achievement, men stand alone. Save your PC rationalizations for yourself, if they make you feel better, but don't expect an objectivist to buy them when they are so obviously errant.

Valerie said at September 12, 2011 3:00 PM:

Hucbald,
Camille Claudel? Mme. Curie? Even now there are those who refuse to credit women for no better reason than that they are women. There are certainly more men at the top in many fields due to the above factors but there are also many more male schizophrenics.

solaris said at September 12, 2011 3:48 PM:

>"Suppose prospective parents 10 or 20 years from now decide to alter the womb environment in a female pregnancy in order to temporarily induce the conditions that CAH causes. Suppose they'll be able to do this without a doctor's help. Will prosecutors try to bring charges against them? If so, for what?"

The questions supposes the existence of a law against the practice. So, for violation of that law.


>"Should it be illegal to substantially alter the degree of masculine or feminine qualities developed in a fetus?"

If "we the people" say it should be illegal, sure. Then it should be illegal. That's how laws work.


>"Do you believe parents should be free to create combinations of cognitive attributes that are currently quite rare?"

Me personally? No, I don't.

TallDave said at September 12, 2011 4:01 PM:

You could do this now, pretty easily, if you wanted to. Just take a couple tribulus caps every day, you'll probably get the same effect.

As to whether people should be allowed to do this... it's one of those questions with two edges: if people shouldn't be allowed to do this on purpose, should they also be forced to accept treatments to prevent this condition from occurring by accident (i.e. naturally)? I don't think there's any coherent moral argument for favoring a roll of the dice over a planned outcome, so rather than make us all normative by law, it's probably better if the gov't just stays out of our wombs.

>>>>if "we the people" say it should be illegal, sure. Then it should be illegal. That's how laws work.

Much of the U.S. Constitution actually exists precisely and expressly to prevent the passage of laws favored by the majority.

solaris said at September 12, 2011 5:10 PM:

>"Much of the U.S. Constitution actually exists precisely and expressly to prevent the passage of laws favored by the majority."

No, very little of the US Constitution exists for that purpose, and the specific cases where "the majority" (actually a very specific subset of the majority, between 51% and 66%) are prevented from enacting laws are very limited. A majority greater than two-thirds may do, quite literally, ANYTHING it wants.

But thanks for repeating the left-wing conventional wisdom.

newscaper said at September 12, 2011 5:40 PM:

Here is precisely where the 'born this way' GL crowd are painting themselves into a corner.

[partial aside -- its nonsense on the face of it because there is very clearly a spectrum of 'hard' to 'soft' homosexuality (sort of biological vs psychological/behavioral) and objectively maladaptive]

Here's the conundrum: if the 'harder' apparently more innate variety is rooted in some quirk of the maternal prenatal environment, rather than the genotype of the embryo itself, then it is more clearly a developmental flaw and not some inherent expression of the individual. Therefore, if it is possible to 'nudge' that environment so the child will be hetero -- and the only window for such treatment is in utero (you can't just let the child reach puberty and decide later) -- then there is no real leg to stand on in the G/L crowd opposing it.

Ryan said at September 12, 2011 7:25 PM:

I wouldn't support it. I'd of course need to analyze the facts further and consider (within reason) all the pertinent nuances of each potential position, that is, if I were to form a strong conviction on the matter; at the moment, however, I suspect the amount of governmental regulation that would be required to prevent disastrous consequences from such a practice (in the long-run, at least) probably cannot be justified.

Imagine what sort of consequences might await the remote future if this were widespread. I'd expect either an unstable runaway of extreme sexual dimorphism or else a mutually-reenforced, overall increase in masculinization. Expecting parents of a male, looking to rear the manliest of possible sons, would doubtless desire to pump the kid full of androgens. Developing females, on the other hand, would likely be directed toward characteristics associated with highly feminine beauty, if not instead routed onto a relatively more secure path with the goal of material success via traits heavy in virility. Nearly all fathers, whether conservative or liberal, wish for the most dominant sons; yet I presume the majority of mothers vary re: their preferences for a daughter, largely according to how well and how much more emphatically the girl could fulfill whichever particular goals they happen to prioritize themselves. A pretty woman who's enjoyed her life is, more often than not, going to opt for qualities consistent with a petite body and coy demeanor, but a less-fortunate tomboy in possession of a rebellious streak, for instance, is usually not about to "perpetuate gender oppression" (or some such nonsense, i.e., penis envy).

I'm wary of toying with Mother Nature when the advantages appear so moderate, the range of consequences so wide, and the predictability so broadly imprecise. For example, increased masculinity might swiftly resort to an environment of greater violence and crime. Or radical dimorphism could just result in a total decline in men willing to function as providers for the ever-weakening and more dependent ladies as abundant cads help make single-motherhood rates skyrocket even faster. Either of those easily renders this a public, not a private, issue.

TallDave,
>>"I don't think there's any coherent moral argument for favoring a roll of the dice over a planned outcome, so rather than make us all normative by law, it's probably better if the gov't just stays out of our wombs.">Camille Claudel? Mme. Curie?those are the aces up your sleeve. So you hold these ladies in the same league as an Aristotle, Newton, Einstein, et al., I suppose. Interesting.

comatus said at September 12, 2011 7:27 PM:

Let's get down to the important issue: just how long are their ring and index fingers? Can't believe they skipped this.

Ryan said at September 12, 2011 7:33 PM:

Oops. The last part should read like this:

TallDave,
"I don't think there's any coherent moral argument for favoring a roll of the dice over a planned outcome, so rather than make us all normative by law, it's probably better if the gov't just stays out of our wombs."

The choices parents make in regards to the womb inevitably manifest on a very social level, soon affecting everyone else, along with their abilities to pursue happiness.

Penny,
What are the sex ratios at those schools? And in case you believe that's not relevant, then explain why any of your mildly interesting anecdotes should be.

Valerie,
Camille Claudel? Mme. Curie?

Exactly! We've come so far, and *those* are the aces up your sleeve. So you hold these ladies in the same league as an Aristotle, Newton, Einstein, et al., I suppose. Interesting.

Zoe Brain said at September 13, 2011 12:22 AM:

It's complex, I'll try to simplify, please bear with me.

First, we do have a population that was exposed to hormones, that alter neuro-anatomy. The drug was DES - DiEthylStilbestrol, and it gave an increase in Transsexuality in XY foetusses of 500 times the norm - plus various other Intersex conditions in both XY and XX foetusses, and some other developmental anomalies too, none of them good.

You'd have to time things just right, and monitor foetal development at the cellular level - something way beyond our capability for the foreseeable future - in order to avoid sequelae such as Transsexuality, Lesbianism, masculinised genitalia, infertility, ambidexterity, autism spectrum disorders. You'd get as other results unique brain patterns in white matter and grey matter distribution, associated with various talents. Basically, you mess around with foetal neuro-anatomy by altering foetal environment at your own risk.

Some reading material about this:

White matter microstructure in female to male transsexuals before cross-sex hormonal treatment. A diffusion tensor imaging study. - Rametti et al, J Psychiatr Res. 2010 Jun 8.
CONCLUSIONS: Our results show that the white matter microstructure pattern in untreated FtM transsexuals is closer to the pattern of subjects who share their gender identity (males) than those who share their biological sex (females). Our results provide evidence for an inherent difference in the brain structure of FtM transsexuals.


Regional cerebral blood flow changes in female to male gender identity disorder. - Tanaka et al, Psychiatry Clin Neurosci. 2010 Apr 1;64(2):157-61.
RESULTS: GID subjects had a significant decrease in rCBF in the left anterior cingulate cortex (ACC) and a significant increase in the right insula compared to control subjects.
CONCLUSIONS: The ACC and insula are regions that have been noted as being related to human sexual behavior and consciousness. From these findings, useful insights into the biological basis of GID were suggested.


“Prenatal hormones versus postnatal socialization by parents as determinants of male-typical toy play in girls with congenital adrenal hyperplasia” Pasterski VL, Geffner ME, Brain C, Hindmarsh P, Brook C, Hines M Child Dev 76(1)p264-78 2005
Data show that increased male-typical toy play by girls with CAH cannot be explained by parental encouragement of male-typical toy play. Although parents encourage sex-appropriate behavior, their encouragement appears to be insufficient to override the interest of girls with CAH in cross-sexed toys.


Sexual Hormones and the Brain: An Essential Alliance for Sexual Identity and Sexual Orientation Garcia-Falgueras A, Swaab DF Endocr Dev. 2010;17:22-35
The fetal brain develops during the intrauterine period in the male direction through a direct action of testosterone on the developing nerve cells, or in the female direction through the absence of this hormone surge. In this way, our gender identity (the conviction of belonging to the male or female gender) and sexual orientation are programmed or organized into our brain structures when we are still in the womb. However, since sexual differentiation of the genitals takes place in the first two months of pregnancy and sexual differentiation of the brain starts in the second half of pregnancy, these two processes can be influenced independently, which may result in extreme cases in trans-sexuality. This also means that in the event of ambiguous sex at birth, the degree of masculinization of the genitals may not reflect the degree of masculinization of the brain. There is no indication that social environment after birth has an effect on gender identity or sexual orientation.


Prenatal exposure to testosterone and functional cerebral lateralization: a study in same-sex and opposite-sex twin girls. Cohen-Bendahan et al, Psychoneuroendocrinology. 2004 Aug;29(7):911-6.
In animals it has been shown that exposure to sex hormones is influenced by intrauterine position. Thus fetuses located between two male fetuses are exposed to higher levels of testosterone (T) than fetuses situated between two female fetuses or one female and one male fetus. In a group of opposite-sex (OS) twin girls and same-sex (SS) twin girls a potential effect of prenatal exposure to testosterone (T) on functional cerebral lateralization was investigated. We hypothesized that prenatal exposure to T would result in a more masculine, i.e. a more lateralized pattern of cerebral lateralization in OS twin girls than in SS twin girls. An auditory-verbal dichotic listening task (DLT) was used as an indirect method to study hemispheric specialization. Firstly, we established a sex difference on the DLT. Compared with SS girls, OS twin boys showed a more lateralized pattern of processing verbal stimuli. Secondly, as predicted OS girls had a more masculine pattern of cerebral lateralization, than SS girls. These findings support the notion of an influence of prenatal T on early brain organization in girls.


Prenatal exposure to diethylstilbestrol(DES) in males and gender-related disorders:results from a 5-year study Scott Kerlin. Proc. International Behavioral Development Symposium July 2005
More than 150 network members (out of 500) with “confirmed” or “strongly suspected” prenatal DES exposure identified as either “transsexual, pre- or post-operative,” (90 members), “transgender” (48 members), “gender dysphoric” (17 members), or “intersex” (3 members).
...
In this study, more than 150 individuals with confirmed or suspected prenatal DES exposure reported moderate to severe feelings of gender dysphoria across the lifespan. For most, these feelings had apparently been present since early childhood. The prevalence of a significant number of self-identified male-to-female transsexuals and transgendered individuals as well as some individuals who identify as intersex, androgynous, gay or bisexual males has inspired fresh investigation of historic theories about a possible biological/endocrine basis for psychosexual development in humans, including sexual orientation, core gender identity, and sexual identity (Benjamin, 1973; Cohen-Kettenis and Gooren, 1999; Diamond, 1965, 1996; Michel et al, 2001; Swaab, 2004).


Sexual differentiation of human behavior: Effects of prenatal and pubertal organizational hormones Sheri A. Berenbaum, Adriene M. Beltz Frontiers in Neuroendocrinology 32 (2011) 183–200
A key question concerns the extent to which sexual differentiation of human behavior is influenced by sex hormones present during sensitive periods of development (organizational effects), as occurs in other mammalian species. The most important sensitive period has been considered to be prenatal, but there is increasing attention to puberty as another organizational period, with the possibility of decreasing sensitivity to sex hormones across the pubertal transition. In this paper, we review evidence that sex hormones present during the prenatal and pubertal periods produce permanent changes to behavior.
There is good evidence that exposure to high levels of androgens during prenatal development results in masculinization of activity and occupational interests, sexual orientation, and some spatial abilities; prenatal androgens have a smaller effect on gender identity, and there is insufficient information about androgen effects on sex-linked behavior problems. There is little good evidence regarding long-lasting behavioral effects of pubertal hormones, but there is some suggestion that they influence gender identity and perhaps some sex-linked forms of psychopathology, and there are many opportunities to study this issue.


There's no such thing as a "male brain" or "female brain" - only brains with different structures that individually match more or less closely the patterns statistically found in those we label "male" or those we label "female". It's usual for everyone to have some structures "male", others "female", it's which structures you're talking about, and the degree of masculinisation/feminisation that makes the difference. Post-natal environment is completely dominant in many areas of behaviour, in others completely irrelevant, in most a "bias" that only affects borderline cases.

Anyway, the next time someone tells you "girls can't do X because they're intellectually not suited because of their biology", you know they're talking rubbish. And the next time someone tells you that "gendered behaviour is 100% a social construct" you know they also are talking rubbish.

Explore Nature said at September 13, 2011 4:16 AM:

Fetal sex hormone abnormalities are causing to many of abnormal sexual developments. If parents can create real masculine boys and real feminine girls rather than growing sexual and gender abnormalities it will help to improve the life time of the human society. And it will certify the long time existence of the human civilization too. We can suggest that as a real progress of science. Growing sexual and gender abnormalities is not progress of science.

http://spiritofnature99.blogspot.com/

AGESILAUS said at September 13, 2011 8:35 AM:

As alluded to above the difference in male and female abilities is not that no women are good at Math, Hard Science or Engineering. They are just very rare. And the reason is that men have broader bell curve for IQ and Math ability. The upper tail is where you find math and science genius. Women have a sharper bell curve with less tail at both ends. The male curve is also offset to the right upper end by a few points. Of course there are women who are successful in these fields, but the only two I know of are Curie and Meitner. Both fairly minor figures in the history of physics.

Of course the flatter curve works at both ends and so male low IQ population is greater than female. Richard Lynn has a good essay on this:

Lynn Essay

The only way to produce more females in the hard disciplines is to lower the requirements in order to fit PC perceptions. Of course this would led to more bridges collapsing and aircraft falling from the skies as well. Physics knows no PC.

cathyf said at September 13, 2011 12:55 PM:

Another method that is already taking place is exposure to phytoestrogens in soy-based foods. Boys born to mothers who are vegetarian (and consume large quantities of soy, especially during pregnancy when adequate protein uptake is vital) have approximately double the chance of being born with certain deformities of the penis. And infants who consume soy formula are getting estrogens just like those "natural" menopause remedies -- which are quite effective because soy delivers hormone-replacement-therapy levels of hormones.

Tom Perkins said at September 14, 2011 6:07 PM:

"No, very little of the US Constitution exists for that purpose, and the specific cases where "the majority" (actually a very specific subset of the majority, between 51% and 66%) are prevented from enacting laws are very limited. A majority greater than two-thirds may do, quite literally, ANYTHING it wants.

But thanks for repeating the left-wing conventional wisdom."

As a practical matter, the majority cannot simply rule, and that is a right wing, Founding era conservative truth.

I have the impression you are stupid, now.

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