The latest evolutionary psychology theory to do the rounds is that blondeness evolved as a selection strategem for women trying to attract scarce mates in the harsh and male-scarce conditions of Ice Age Europe. According to this report in the Times, the theory has been formulated by an anthropologist, Peter Frost. His supporting argument is that blondeness is a signal of high levels of oestrogen. I suppose I should wait for the article which is supposed to come out in Evolution and Human Behaviour, but I can’t resist pointing to an obvious hole and an alternative explanation.
The obvious hole is that blond(e)ness is not a sex-linked characteristic. If light hair colour signals high oestrogen, blond men should have a lot of trouble attracting mates. Tempted as I am by this hypothesis, I can’t say I’ve seen any evidence to back it up.
The alternative explanation (not at all novel) is that fair hair arose in conjunction with pale skin, as a straightforward physical adaption to the move away from the tropics – less need for pigment, or maybe more need to absorb vitamin D.
The Times article also gets bonus points for repeating the claim (which I’ve seen doing the rounds for decades) that blondes will become extinct some time soon because the relevant genes are recessive. Those making this claim should go back to their high school text books and look at Mendel’s peas. Remember how the recessive phenotypes turned up again in the second generation?
After writing this, I found a piece by Frost here. He has a response (unconvincing in my view) to the physical adaption theory, and doesn’t raise the oestrogen idea at all. In this piece he argues, a bit more plausibly, that the harsh environment selected for colour polymorphism, rather than any particular colour scheme.
fn1. I know I’m always bashing this stuff, but only because so much of it is silly. Some aspects of EP, like Pinker’s theory that we have evolved highly advanced mechanisms for lying and lie-detection, seem quite plausible to me.