I have to admit, I've never had much time for sociobiology or its close relative, evolutionary psychology. It's not that I think there's anything wrong with seeking evolutionary explanations for social behaviour—how could I, when Darwin himself predicted similar studies:
In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation. Light will be thrown on the origin of man and his history.
The problem I have with sociobiology is the same problem I have with psychology in general, and sociology in particular: it tries so hard to be recognised as a rigorous, scientific discipline, but any armchair hypothesist can come up with a sociobiological explanation for pretty much any behaviour they care to think about. And because sociobiology often provides simple (and, in some cases, over-simple or obvious) explanations for quirky human behaviour, any crackpot theory emanating from a university department with an -ology suffix is pretty much guaranteed plenty of media coverage—especially if it involves sex: the punters (and lazy science correspondents) just love it!
I appreciate this is being totally unfair to serious sociobiologists. In my defence, however, I would add that most serious sociobiological studies I have read about left me thinking that's all very interesting, but so what?
There was a typical example of it this week. Sociobiologists in Norway published a serious academic paper entitled Why do blue-eyed men prefer women with the same eye color? It's all good stuff, and received plenty of press coverage. Their hypothesis (supported by, as far as I can tell, a well-designed experiment) is that blue-eyed men tend to be attracted to blue-eyed women because blue eyes are the product of recessive alleles; so choosing a mate with blue eyes means that any offspring they have with her must also have blue eyes. So blue-eyed men who have children with blue-eyed women can be slightly more confident—possibly only subconsciously—that their blue-eyed children are their own (and, conversely, will know for certain that any brown-eyed children are not theirs). On the other hand, brown-eyed men, whose eye colour is based on dominant alleles, can end up having children with eyes of either colour, so there is no genetic reason for them to have a preference for any particular eye-colour when selecting a mate.
Does this tell us anything particularly important about what it is to be human? Is eye colour now, or has it ever been, a major factor in mate selection for males with blue eyes? Does it come anywhere near more traditional visible sexual factors? Somehow I doubt it. The sociobiologists carrying out the study are not suggesting that whatever genetic benefits there might be are sufficiently strong to make it a positive evolutionary advantage to have blue eyes (in which case, there would presumably be selective pressure for there to be all sorts of other eye colours associated with recessive alleles); they are simply saying that, given that there is a visible (possibly non-adaptive) trait that is associated with recessive alleles, males who happen to have that trait appear to have a slight preference for females who also happen to have it.
Which is all very interesting, but so what?
In fact, I'm not entirely convinced that this study establishes categorically that there is a clear genetic reason for blue-eyed men's preference for blue-eyed women. I can certainly imagine alternative, cultural explanations for such preferences—although they wouldn't be nearly as neat (or newsworthy) as the sociobiological interpretation, and I don't have an armchair to hand at the moment.