When Men Behave Badly: The Hidden Roots of Sexual Deception, Harassment, and Assault

by David M. Buss

Consider this thought experiment. You are interviewing a newlywed man in a study about his sexual attitudes. You explain to him that although sexual jealousy evolved partly to solve the problem of paternity uncertainty, his blushing bride is taking highly effective birth control pills. Moreover, in the unlikely event that she gets pregnant (less than 2 percent chance if used as directed) you can conduct a DNA test to be 100 percent sure the child is your own. Therefore, the main adaptive rationale for the existence of sexual jealousy is entirely absent. Paternity uncertainty is an ancient adaptive problem that is no longer relevant. After you explain this, you ask the man: “Would you be okay with another man having sex with your wife this evening, now that you know that there’s no need for sexual jealousy, as long as there is a guarantee that she won’t leave you?” Would most men be okay with other men having passionate sexual intercourse with their beautiful brides or trying out different sexual positions with them? If this thought experiment doesn’t convince you of the answer, our empirical studies might. When we brought men into the physiological lab and asked them to imagine their pill-taking wives or girlfriends having sex with other men, their physiological distress levels spiked—heart rate, sweating, and corrugator contraction (frowning) went through the roof. When we watched the experiment unfold through the one-way mirror, we observed some men starting to vibrate. ...