America does love a good sex scandal, almost as much as the British do, and the Petraeus, um, affair has been an especially juicy one.

It’s been so complicated, in that reality-show kind of way, that we need charts depicting who’s connected to whom.The difference between social and sexual monogamy is partly chemical, as was illustrated recently in a fascinating experiment. You may have missed it while being steeped in Jill Kelley news, but the Journal of Neuroscience released a study earlier this month about the effects of the neurochemical oxytocin on the behavior of monogamous males.

Rather than approach the attractive woman, as one might anticipate given oxytocin’s reputation, the men in monogamous relationships who received oxytocin tended to keep her at a distance compared to men who received placebo squirts. Oxytocin had no effect on single guys.