Human desire is just as remarkable in that it leads to sex and intimacy unrelated to procreation. Long before the birth control pill revolutionized intimate life by freeing sexual behavior from reproductive outcome, the same was happening in human evolution. Females of our closest primate relatives advertise their reproductive readiness with swollen, colorful sexual regions—displays that shock and astonish in the primate section of your local zoo. Human females, in contrast, have evolved concealed ovulation. As a result, women and men do not necessarily know whether their desire will lead to reproductive outcome (although a woman is more likely to initiate sex, masturbate, have affairs, and be accompanied by her husband during ovulation; and pole dancers earn bigger tips, Geoffrey Miller has recently found, at the peak of their ovulation). Concealed ovulation evolved, we now know, to prevent stepfather infanticide, which is unnervingly common in mammals, and seen in many rodent species, lions, and many primates. Concealed ovulation keeps males guessing about whether offspring are theirs, thus reducing the likelihood of infanticide. Concealed ovulation also allows women and men to have sex throughout the female’s cycle—an ongoing incentive for the male to remain in a relationship and contribute to the raising of such resource-dependent, vulnerable offspring.
The specific language of desire, which propels potential partners toward one another, has been documented by Givens and Perper. These researchers spent hundreds of hours hiding behind ferns and jukeboxes, laboriously documenting four-or five-second bursts of nonverbal behavior amid the lambent light and Lionel Richie tunes of 1980s singles bars. They homed in on those microscopic behaviors that predict whether women and men will pursue a romantic encounter—a shared drink, an exchange of phone numbers, leaving the bar with buoyant step, arm in arm.
In the initial attention-getting phase, women walk with arched back and swaying hips, amplifying the extent to which their bodies take on that platonic form of beauty—the hourglass figure. Women resort to the well-known universal—the hair flip—which dominates the field of vision of the male of interest, who is nonchalantly sipping his third Bud. Women (and men) smile coyly, lips puckered, head turned away, but eyes dropping in to make eye contact for a millisecond or two.
Men counter with behaviors that amplify their physical size and assumed resource-holding potential. They rock back and forth on their heels and roll their shoulders. They raise their arms with exaggerated gestures, in ordering a round of drinks or stretching out, to show off their well-developed arms, the broad expanse of their shoulders, or expensive watches or prep-school pinkie rings. These brief signals honor time-honored principles in the game of sexual selection. The woman is drawing attention to her curves, fine skin, and full lips—signs of her sexual readiness and reproductive potential. The man is signaling that he has stature, resources, and good genes, appealing to the woman whose desire is conditioned by an awareness of the enormous costs of pregnancy, childbirth, and breastfeeding, which would be offset by a man of means and justified by a man with good genes.
Like courtship, momentary flirtation progresses toward more intimate phases. In the recognition phase, women and men gaze intently at each other; they express interest with raised eyebrows, singsong voice, melodious, voiced laughter, and subtle lip puckers. They turn to the exquisite language of touch, and all those receptors under the surface of the skin, to explore their interest in each other with provocative brushes of the arm, pats on the shoulder, or not-so-accidental bumps against one another that safely occur in the aftermath of a joke or in a pleasant, joshing-around tease. A slight touch to the shoulder that is ever so slightly firmer and more enduring than a polite pat reveals a desire beyond the typical exchange between friends or new acquaintances.
If all of this proceeds well, the potential partners move to the keeping-time phase. They begin to mirror each other’s glances, laughter, gaze, gesture, and posture, as they share jokes, order drinks, disclose embarrassing snippets of the past, and search for commonalities. This kind of behavioral synchrony creates a sense of similarity, trust, and merging of self and other. In Plato’s view, the two souls, having separated at birth but now reunited, are forming the perfect union with one another.
In many species, courtship behaviors stimulate the biology of reproduction. For the tree-dwelling African dove, flirtatious coos and head bows trigger the release of estrogen and luteinizing hormone in the female, and eventually ovulation. A stag’s roar stimulates females to go into heat faster. The lowly snail shoots darts into potential sexual partners, which activates the snail’s sexual organs (I dare not describe them). In humans this language of passion stimulates the experience of desire. In the throes of this kind of love, people experience an entirely different sense of time and a disarming loss of personal control and agency. A metaphorical switch in the mind is turned on (and the voice of cost-benefit, conventional rationality is turned off). People feel blown away, swept off their feet, knocked out, ill, feverish, and mad. They may eat and bathe less, stop seeing friends, neglect their homework and bills. The old definitions of the self are turned off, to make way for the establishment of an entirely new identity, one that emerges in the early delirium and upheaval of pair-bonding relationship and which will rearrange their lives.
This language of desire carries the couple toward a different kind of consummation than that observed in other species. The couple will likely make love face-to-face, unusual in the primate world. They will have sex in private. And alongside desire, our research finds, they will feel a deep sense of anxiety. The woman will wonder whether her new partner resembles the male caricatured all too readily in scientific research, the male eager to pursue short-term sexual strategies (one-night stands) to dispense with his daily production of 200 million sperm (in one study, 75 percent of college males were willing to go home with a female experimenter they had just met while walking on campus, and who had asked whether they were interested in a quickie). The man will feel his own anxiety, perhaps sensing that he is unlike any other primate in the degree to which he will be expected to sacrifice, to forgo other reproductive opportunities, and devote resources to his offspring, whom he will, again unlike any other primate, recognize as his own. They await the warm surround of romantic love to shut down these anxieties.
OPEN ARMS AND MOLECULES OF MONOGAMY
Each year 2.3 million couples wed in the United States. The average cost of a wedding is $20,000, which exceeds the average life savings of any American you might pick off the street. Guests lists are negotiated, dresses fitted, invitations embossed and mailed, appetizers and music selected. What follows is a surreal day of rapturous emotion, fathers crying, mothers spilling their glasses of wine, ex-lovers smoldering, recalled verse, besotted smooches, best friends in arms, and dancing children.
The wedding ceremony could rightfully be thought of as the most elaborate, expensive ritual in human history to fail. Approximately 47 percent of those individuals who stand at the altar, suffused with lofty emotions, uttering vows in hallowed words of devotion, will divorce, and they’ll often go down in flames of hatred and litigation. Very often they’ll divorce within a year or two of the ceremony, giving each other the finger, as did the divorcing parents of a friend of my parents’, in the county courthouse’s courtyard, or uttering “Tu es mort” as they sign the papers.
Or, you could think of the wedding ceremony as an astonishing success. Half of marriages make it. In spite of frequent surges of youthful desires and the mundane complexities of marriage, estimates of adultery suggest that only 11 to 20 percent of married partners have extramarital affairs. Compare that success rate in taming nonmonogamous sexual impulses with recent studies of abstinence programs provided to middle-and high-school students. These expensive, sophisticated products engineered by well-meaning social scientists fail abominably, and often lead teenagers to be more inclined to have sex or unsafe sex after such indoctrination.