Tuesday, March 28, 2006

Pregnant Moms to Start Taking Steroids

James Watson has been talking about how we should use eugenics (see this Charlie Rose show), to improve the genes of humanity. Watson seems to feel that we will find a gene for everything: an intelligence gene, a gregarious gene, a gay gene, a left handed gene, a criminal gene and more. And as we find these genes then we can use genetic screening and genetic manipulation to improve these genes.

So I was surprised to come across a couple articles talking about how the level of prenatal testosterone affect important features. This implies that there is more to the whole nature vs. nurture debate than just genes and the way we are raised. There is this in between stage when we are in the womb that affects the way we turn out. Instead of talking about genetic modification and designer genes, maybe we should be talking about designer steroids that affect the level of hormones in the amniotic fluid.

Side note: Anyone who spends 5 minutes looking at James Watson and listening to him speak, will come away wondering if he should really be the poster boy for eugenics. He is not quite as bad as Hitler promoting his Aryan ideal which he looked nothing like, but lets just say that I don't see the Watson sperm being a hot seller at the sperm bank. Anyway, maybe that is just me.

Simon Baron-Cohen points out in the New York Times:

It has also been found that the amount of prenatal testosterone, which is produced by the fetus and measurable in the amniotic fluid in which the baby is bathed in the womb, predicts how sociable a child will be. The higher the level of prenatal testosterone, the less eye contact the child will make as a toddler, and the slower the child will develop language. That is connected to the role of fetal testosterone in influencing brain development.

Males obviously produce far more prenatal testosterone than females do, but levels vary considerably even across members of the same sex. In fact, it may not be your sex per se that determines what kind of brain you have, but your prenatal hormone levels. From there it's a short leap to the intriguing idea that a male can have a typically female brain (if his testosterone levels are low), while a female can have a typically male brain (if her testosterone levels are high). That notion fits with the evidence that girls born with congenital adrenal hyperplasia, who for genetic reasons produce too much testosterone, are more likely to exhibit "tomboy" behavior than girls with more ordinary hormone levels.
Or Sandi Doughton in the Seattle Times:
But rats, hamsters, ferrets and other lab animals flip-flop their sexual behavior when scientists manipulate the hormones they're exposed to before birth. Such experiments would be unethical in people, but some rare medical conditions offer human parallels.

A high proportion of girls with a disorder that causes them to secrete male hormones before birth grow up to be lesbian. About 40 case studies have shown boys who are surgically altered and raised as girls because of genital deformities are overwhelmingly attracted to females once they reach puberty; indicating sexual orientation is determined very early in life and is difficult to alter.

"Every time you find a body marker that gives an indication of prenatal testosterone exposure, lesbians on average are more masculine than straight women," Breedlove said. "This can't be a fluke."

Patterns aren't as clear in gay men, with some hints they may be exposed to either less or more testosterone before birth.
Want a son who is good at math and sciences? Time for some amniotic testosterone steroids. Or maybe you would rather have a more outgoing social son, in that case lets get those levels down. Afraid that your dagger might be gay, or now that lesbianism is hip, maybe you want that? Either way time to take a steroid to change those hormonal levels.

And it may not just be the hormones they need to look at, as 60 Minutes reports:
While biologists look at hormones for answers about human sexuality, other scientists are looking for patterns in statistics. And hard as this is to believe, they have found something they call "the older brother effect."

"The more older brothers a man has, the greater that man's chance of being gay," says Bailey.

If this comes as a shock to you, you're not alone. But it turns out, it's one of the most solid findings in this field, demonstrated in study after study.

And the numbers are significant: for every older brother a man has, his chances of being gay increase by one third. Older sisters make no difference, and there's no corresponding effect for lesbians. A first-born son has about a 2 percent chance of being gay, and the numbers rise from there. The theory is it happens in the womb.

"Somehow, the mother's body is remembering how many boys she's carried before," says Breedlove. "The favorite hypothesis is that the mother may be making antibodies when she sees a boy the first time, and then affect subsequent boys when she carries them in utero."
Beyond the hormone levels, looks like there might be other things like the mother's immune system that affects how children turn out. Anyway that you look at it, eugenics and genetic manipulation by itself does not allow you to change all the characteristics of humans that we would think of as natural born. It is going to be interesting to see what science will find out about the root causes of these characteristics.

1 comment:

The Wilkernator said...

Incredible how our society cares about appearence more than health.

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