Valentine's Day News: New Study Says Kissing Your Sister is Bad

To be perfectly honest — and apparently, gross — I never really knew what the big deal is. Besides homozygosity. I'm an only child, plus I've had relatives try to set me up with my cousins, so I just always fantasized that if I had a generic hot sister who was into that sort of thing, what the hell, right? What's a little universal cultural taboo between siblings engaged in self-exploration?

But researchers at UC Santa Barbara just had to go around ruining my fantasy, and also about three-hundred Veronica Mars fanfics. I love it when science gets its rational self applied to what we take for granted, and this story fascinates me. Evolutionary biology predicts that we humans ought to have some mechanism for guessing who shares our DNA: we ought to be quicker to help our kin because their reproductive success improves our standing in the gene pool, unless their reproductive success is with family, which weakens the gene pool. What the researchers found is that you can blame your whole incest squeamishness on, of course, Mom.

The good news is that, contrary to what Freud claimed, you don't have an ingrained crush on your mother, precariously tipping between your subconscious desire to return to the womb and social custom and pressure getting you to marry outside of your kin group. You form this notion of a kin group early in your life, watching your mother take care of your siblings, or, in terms of modern non-nuclear American families, your "siblings:" the people you grew up with, and the thought of doing it with someone your mom cared for gives you the willies.