We have long known that men have a genetic, evolutionary impulse to cheat, because that increases the odds of having more of their offspring in the world.
But now there is intriguing new research showing that some women, too, are biologically inclined to wander, although not for clear evolutionary benefits. Women who carry certain variants of the vasopressin receptor gene are much more likely to engage in “extra pair bonding,” the scientific euphemism for sexual infidelity.
I’m not surprised. My informal interviews with women indicates a bimodal distribution. Either women 50 years and older have had a relatively small number of sexual partners, less than 10 or else dozens or, sometimes, many hundreds.
See also my post here.