I never had much time for evolutionary psychology. It's not that I think modern-day human behaviour has nothing to do with our evolutionary heritage; it's just that it's far too easy to invent plausible yet ultimately untestable evolutionary explanations for pretty much any human behaviour you care to mention. And it's so much fun! Particularly if it involves sex.
There was a great example of this in New Scientist the other week. Unfortunately, most of the article in question is hidden behind a subscribers-only paywall (why do they still insist on doing that?). So here is my highly condensed and edited summary:
Researchers have found that women have the sexiest walk during the part of the monthly cycle when they are least fertile.
Video analyses of women's gaits showed a correlation between the way the women walked and their time of the month. Forty men were shown the same images of the women walking, rating those in the less fertile part of their cycle as having the sexiest walks.
Previous research investigating men's response to fertile women focused on signals such as smells and facial expressions, which can only be detected at close range (i.e. by the men the women have decided are worth having children with and have therefore allowed to get close to them). The advantage of having a less sexy walk around the time of ovulation is that it allows a woman to hide her fertile period from undesirable men (i.e. those who can only admire her from afar), who might take advantage of her at that time.
"If women are trying to protect themselves from sexual assault at times of peak fertility, it would make sense for them to advertise attractiveness on a broad scale when they are not fertile," says Meghan Provost, one of the researchers.
Ah, yes, but…
If there's anything in this evolutionary psychology malarkey, shouldn't it work on both sexes? What possible evolutionary advantage could there be for a man to find a woman's wiggly (i.e. non-fertile) walk sexy? Shouldn't he have evolved a preference for the non-wiggly walk that she performs in her most fertile period?
But I'm sure there will be some perfectly plausible yet ultimately untestable evolutionary explanation for why us chaps should allow ourselves to be duped in this way.