-
If a woman's stressed during pregnancy will she not have a son? A piece in the new issue of the Economist suggests a connection between maternal stress and a baby's gender. Here's the theory: First World women are 5 percent more likely to have a male child than their counterparts in developing countries, but that gap's been closing lately. That could be because women under stress are more likely to give birth to girls. A few studies have shown that women are more likely to have girls when they conceive in war zones, right after natural disasters, or after the loss of a loved one. One tempting bit of association: Fewer baby boys were born to New York City mothers who got pregnant the week after the Sept. 11 attacks.
I wonder how this fits into our discussion on evo pysch. A Danish scientist who's researched the effects of chronic stress on reduced male birth rates (as opposed to stress brought on by a catastrophic event), suggests that the reasons for stressed mothers having fewer boys "might be adaptive" because
the chances are that a daughter who reaches adulthood will find a mate and thus produce grandchildren. A son is a different matter. Healthy, strapping sons are likely to produce lots of grandchildren, by several women-or would have done in the hunter-gatherer societies in which most human evolution took place. Weak ones would be marginalised and maybe even killed in the cut and thrust of male competition. If a mother's stress adversely affects the development of her fetus (as it is likely to do) then selectively aborting boys, rather than wasting time and resources on bringing them to term, would make evolutionary sense.
The "cut and thrust of male competition?" I hear echoes of Dana's monkey-men.
Join the Fray: our reader discussion forum
What did you think of this article?