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  • Did your genes make you do it?

What a relief to see that some serious scientific work is being done on the perplexing question of why, why, why women would ever be unfaithful to their husbands.

As author and clinical psychiatry professor Richard A. Friedman writes in a New York Times op-ed titled “Infidelity Lurks in Your Genes,” male promiscuity is firmly rooted in “genetic, evolutionary” logic.

It’s “pretty straightforward,” Friedman says: the more women they screw, the greater “the odds of having more of their offspring in the world.”

No further explanations needed.

For females, however, he says there have never been any “clear evolutionary benefits.” So what possibly could have motivated the 10 to 15 percent of wives who confided to NORC (the research center at the University of Chicago) that they “actually cheat on their partners”?

What’s in it for them, he wonders, on his way to reporting that we might now know. According to “intriguing new research,” Friedman claims, infidelity may be driven by “variations in the vasopressin gene.”

But only in women.

Never mind that “it’s not clear why there was no relationship between the vasopressin gene and promiscuous behavior in men.” But there’s a good reason to take the findings seriously: it worked in voles. Shoot vasopressin directly into their little rodent brains and their wandering days are over.

Infidelity could also have something to do with dopamine deficits, he reports.

And if you’re thinking there might be some evolutionary benefit to sperm supply diversity and the potential quality upgrade advertised by, say, a hunky physique? Nah. Not in this report, anyway.