Contraceptive Pill Update: Even More Nonsense Than Scents

Speaking of pills, here's a quick followup on my earlier post about hormonal contraception, smell, and partner preference. Amanda Schaffer of The XX Factor at Slate.com says (emphasis hers)

In the past, some research found that women tended to prefer the smell of men whose MHC makeup differed more extensively from their own. That result remains controversial, but from an evolutionary perspective, it makes for a good story. When women mate with less similar men, their kids may have more robust immune systems that can better fend off a wide range of diseases. In theory at least, that advantage may have helped to shape women’s tastes over time. As for the pill, if it were to skew preferences toward MHC similarity, women might smile on less genetically favorable partners, leading to problems in the long run. When women stop taking the pill, for instance, their tastes might shift again, resulting in “the breakdown of relationships," as one researcher speculated. Hence the maelstrom about women choosing the “wrong” men.

Strikingly, however, the current study fails to confirm the premise of that whole story. When women smelled men's T-shirts at the outset, before any of them took the pill, they showed no preference for men with more MHC difference. That is, they did not exhibit the supposed tendency that the pill supposedly disrupts. What’s more, when women taking the pill smelled the T-shirts again, they showed no preference for men with more MHC similarity. Yes, the pill-takers tended to rate the smell of MHC-similar men more favorably than they had before. But to repeat: They still didn’t prefer the similar guys overall. Despite the hype, then, this study’s findings are limited – and pretty messy.

Of course smell can play a role in romance. And the scent of MHC difference could turn out to be one factor – of many – that influences women’s choices. But really, when it comes to searing insight into longing and romantic crisis, T-shirt sniffing has nothing on Flaubert.
She said it here.

Again the "in the past" studies (more info at Wikipedia) are neither terribly new (they go back to the 1970s) nor even terribly controversial. But also not terribly determinative of mate selection unless you're a rodent. Also, if I recall correctly a confounding factor is that with mate selection the actual preference is for potential mates that are somewhat *but not too* different.

What *is* different is that while the authors of the current study don't seem to be participating in it there's a large and concerted conservative political assault on hormonal contraception. Oh, and along *those* lines, good news out of California today.