Born to Be Good: The Science of a Meaningful Life

Consider the kiss or, in Facial Action Coding System terms, the simple lip pucker and lip funnel (AUs 18 and 22), and, in more lascivious moments, the tongue protrusion (AU29). It is well known that people kiss differently in different cultures. In some cultures, kissing in public is rare or nonexistent, as with certain Amazonian tribes or the people of Somalia. There are different kisses for friends, political officials, children, and romantic partners. A visit to kissingsite.com will tell you there are thirteen kinds of romantic kisses, from the suck on the chin to quietly sharing breath. And there are, of course, individual extremes: One Italian couple kissed continuously for 31 hours, 18 minutes, and 33 seconds. In 1991 Alfred Wolfram kissed 8,001 people in eight hours at a Renaissance fair in Minnesota.

This sublime variety might seduce you into thinking that the kiss is a cultural artifact, like the peace sign, BlackBerry, fork, or necktie: Some cultures have it and others do not, and members of different cultures vary widely in their uses of the artifact. In fact, certain anthropologists have made such an argument about the kiss. Based on the absence of portrayals of kisses in cave paintings, they have argued that humans invented the kiss around 1500 BC, and that it spread from India westward. It was widely popularized by the Romans, who integrating kissing into numerous public rituals, such as kissing the ring of the emperor or other sacred objects.

This argument ignores what we learn by cross-species comparisons of the kiss. Our primate predecessors premasticate food to make it more digestible for the young, and deliver this softened caloric mass to the young with a kiss. The same has been documented by Irenäus Eibl-Eibesfeldt of preindustrial human cultures. Parents will chew up food and pass it on to their young offspring, mouth to mouth. Food sharing, then, is the original evolutionary context of the kiss. Primates, in their cooperative ways, have extended this rewarding display to acts of affiliation: They rely on lip smacks and pouts as signals to prompt others to come closer. The human kiss has its roots in the food sharing of our close primate relatives.

What evolutionary forces gave rise to gaze aversion, head turns and face touches, and that coy smile of embarrassment? I found answers from studies of appeasement and reconciliation processes in nonhuman primates. Frans de Waal has devoted thousands of hours to the study of what different primates—macaques, chimpanzees, and bonobos—do following aggressive encounters. Prior to this work, the unquestioned assumption was captured in the dispersal hypothesis: Following an aggressive encounter, combatants would move away from each other as far as possible, a safe, self-preserving, and adaptive thing to do.

Yet de Waal observed the opposite pattern of behavior. Instead of moving away from one another after conflict, the primates he was observing were more likely to spend time in the presence of one another. This would make sense for species that are so dependent upon one another to accomplish the basic tasks of survival and reproduction. With more careful observations, de Waal discovered how primates reconcile during conflict, and reestablish cooperative relations. In the midst of conflict or aggression, the subordinate or defeated animal first approaches and engages in submissive behaviors, such as bared-teeth displays, head bowing and bobbing, and grunts. These actions quickly prompt affiliative grooming, physical contact, and mutual embraces, reconciling the warring parties. In nonhuman primates, these reconciliation processes transform life-threatening conflicts into affectionate, backslapping embraces within seconds.

When I reviewed forty studies of appeasement and reconciliation processes across species, from blue-footed boobies to 4,500-pound elephant seals, the evolutionary origins of embarrassment became apparent: It is a display that reconciles, that brings people together in contexts of distance and likely aggression.

Let’s take it behavior by behavior, in the Darwinian fashion. Gaze aversion is a cut-off behavior. Extended eye contact signals continue what you’re doing; gaze aversion acts like a red light, terminating what has been happening. Our embarrassed participants, by quickly averting their gaze, were exiting the previous situation. They were signaling an end to the situation for obvious reasons: embarrassment follows actions—including social gaffes, identity confusion (forgetting someone’s name), privacy violations (walking in on someone in a bathroom stall), and the loss of body control (the prosaic fart or stumble)—that sully our reputations and jeopardize our social standing.