July 1, 2001

9:36 AM

Evolutionary psychology anyone?It seems that more males are born during (and just after) wars and more females are born during peacetime. Adaptive group evolution or just speculative extrapolation? Jim Holt of Linguafranca explains.
posted by kliuless (11 comments total)

During wartime, women adopt more dominant, "masculine" roles—Rosie the Riveter, that sort of thing—and this may well tip their hormonal balance

and this is where the argument breaks down for me.

during wartime, women are under a lot more stress from fear of themselves or their loved ones being killed. I would think that this adrenaline would account for any chemical changes that might affect hormonal levels. - rcb
posted by rebeccablood at 11:57 AM on July 1, 2001

Most of what he says doesn't sound too outrageous compared to what I've been taught at uni, but I'd be interested to know where he got his data from for the claims he made in his last paragraph about the skewed sex ratio for second children.

Just seems like a bit of a just-so-story to me. In fact, the whole idea of environment of evolutionary adaptiveness and all that has come under fire recently.
posted by adrianhon at 1:06 PM on July 1, 2001

Doesn't Dawkins lay this to rest (as rubbish)? I thought it was in The Extended Phenotype, but can't find it now.
posted by andrew cooke at 1:36 PM on July 1, 2001

I haven't read it myself but just because Dawkins says something doesn't mean it's true (it doesn't mean it's false either, but you know what I mean).
posted by adrianhon at 2:26 PM on July 1, 2001

I know, but (1) I thought someone might fill in the details to enlighten us all and (2) it sheds some light on the "loony neo-Darwinists" angle (deensing on where exactly you place him).
posted by andrew cooke at 3:44 PM on July 1, 2001

PS deensing -> depending and it's a very good book (best science book I read last year).
posted by andrew cooke at 3:45 PM on July 1, 2001

it's pretty easy to study the theory of hormonal influences on sex selection at conception. first one must define what one will hold to be "masculine" roles, and then study those women who have children. i'm not sure what the answer will be.

i have heard the theory that at certain times of ovulation, you're more likely to conceive a boy versus a girl. i'm not sure that has much relevance to the subject at hand, though of course your hormones will be in flux during ovulation at any rate.
posted by moz at 3:46 PM on July 1, 2001

Incidentally, there's been a study carried out very recently that showed that increased levels of testosterone during pregnancy can be correlated to more 'tomboyish' behaviour in girls, where 'tomboyishness' is measured as a factor of the sex ratio of the girl's friends, whether she does a lot of sport, all sorts of stuff. Haven't read the report myself but it makes sense.
posted by adrianhon at 4:50 PM on July 1, 2001

These hormones, it is further conjectured, affect the relative success of the X and Y sperm in getting to the egg.

I'd rather conjecture that there is a relationship between the success of the Y sperm and the frequency of love-making during and immediately after wars.

And one conjecture is as good as another in these arguments.
posted by caraig at 5:56 PM on July 1, 2001

caraig: I'd rather conjecture that there is a relationship between the success of the Y sperm and the frequency of love-making during and immediately after wars.

huh? wouldn't that just result in *more* children? I thought the observation was that more than usual of the children born are boys. - rcb
posted by rebeccablood at 6:17 PM on July 1, 2001

Lingua Franca is the National Enquirer of academe. I don't even have to click the link to know where I stand on this.
posted by rschram at 8:34 AM on July 2, 2001