"Mirroring" is about reading and experiencing another person's emotions as if they were her own, Brizendine says, allowing a woman to become "a human emotion detector." "Although most of the studies on this topic have been done in primates," she writes, "scientists speculate that there may be more mirror neurons in the human female brain than in the human male brain." Our old F-15 friend Sarah's brain, for instance, "will begin stimulating its own circuits as if her husband's brain were her own." The implication is that extra mirror neurons make women like Sarah innately more empathetic than their hapless husbands.

But megacaveats are in order here. For one thing, the role of mirror neurons in humans is not well-established. Some very smart people maintain that they are largely a nice metaphor or myth. Beyond that, Brizendine offers virtually no evidence for the claim that women have more mirror neurons than men do. Since her book's publication, a small amount of work has suggested some difference in mirror neuron activity in men and women. But that work is preliminary. (Click here and scroll down for details.)