Supernormal Stimuli: How Primal Urges Overran Their Evolutionary Purpose

Have you ever wondered why some men choose pornography over actual women? Why so many people watch Friends instead of going out with their own buddies? Why a person would “feed” a plastic Pocket Pet while shirking real duties? Why both sides of every war see the other as the aggressor against whom their “Department of Defense” must respond?

Harvard evolutionary psychologist Deirdre Barrett explains how human instincts—for...