American Scientist

The Dangerous Passion: Why Jealousy Is as Necessary as Love and Sex. David Buss. 288 pp. Free Press, 2000. $25.

I'm OK. You're OK. And maybe, in moderate doses, even jealousy's OK.

The fabled green-eyed monster gets a makeover by University of Texas psychology professor David Buss, who labels excessive jealousy, the kind that leads to stalking, beating or murder, "extraordinarily destructive." But moderate jealousy, he writes, "signals commitment." Moreover, "the total absence of jealousy, rather than its presence, is a more ominous sign for romantic partners. It portends emotional bankruptcy."

Buss treats jealousy as the co-evolved ally of love:

It is unlikely that love, with the tremendous psychological investment it entails, could have evolved without a defense that shielded it from the constant threat from rivals and the possibility of betrayal from a partner. Jealousy evolved to fill that void, motivating vigilance as the first line of defense and violence as the last.

The subtitle, by conferring respect on jealousy, makes an appearance by Buss on Oprah seem inevitable. In fact, it's unlikely she'll be able to resist the gossip value of a number of the research-based findings the book sets forth. To wit:

Men are more upset than women by imagining, seeing or hearing about their lovers in physical liaison with others. Women's jealousy is more aroused by the thought of a partner's being emotionally intimate with another woman.

For affair partners, women prefer symmetrical men—a sign of good genes—to asymmetrical ones, according to research by Steve Gangestad and Randy Thornhill, of the University of New Mexico. Writes Buss, "Men who are rather asymmetrical are especially prone to being cuckolded by their more symmetrical rivals." In other words, in affair-partner competition, Denzel Washington will likely whip Lyle Lovett, of the lopsided grin. Taking the study a step further, Gangestad and Thornhill had symmetrical and asymmetrical men wear T-shirts for two days. Next, they had ovulating women judge the T-shirts for odor. The women decided that the T-shirts of the symmetrical men smelled better than those worn by the asymmetricals. (The males whose T-shirts were, after two days, harvested for study purposes had been instructed not to eat any fragrant food such as garlic or onions.)

Newlywed women cope with the threat of abandonment by working to enhance their physical appearance. Men, on the other hand, tend to display resources, buying spouses flowers, jewelry or fancy meals.

Buss also sets forth what he labels "myths about jealousy." One is that jealousy is "a social construction," a second that it results from capitalism and involves mistaking human beings for personal property, a third that it arises from low self-esteem, immaturity or character defects, and a fourth that it is a "pathology." He concedes that some of these "myths" contain "grains of truth." Buss agrees that jealousy is sometimes pathological, "a product of brain injury from boxing or warfare," and does vary in its expression from culture to culture.

But raising these "myths" serves Buss mostly as a means of introducing his own belief that to understand jealousy "we must peer deep into our evolutionary past to a time before computers, before capitalism, and even before the advent of agriculture."

Indeed, jealousy is scripted so deeply into our biology that it helps explain varieties of sperm that differ both morphologically and functionally. Buss gleefully reports that there are, among sperm, fast swimmers ("Mark Spitzes of the sperm world") and "kamikaze sperm ... poorly designed for swimming speed" that wrap themselves "around the egg getters [of male rivals] and destroy them, committing suicide in the process. These physiological clues reveal a long evolutionary history in which men battled with other men, literally within the woman's reproductive tract...."

Despite this amassing of research, Buss admits that jealousy has been "largely neglected" by social scientists. Moreover, his point of view is not universally shared. I asked University of Kansas psychologist Rick Snyder, who is studying forgiveness, about the necessity of jealousy. "The notion that jealousy at any level is useful," Snyder says, "is not consistent with the social science literature."

Snyder, author of The Psychology of Hope (1994), calls it "bad logic" to argue that a character trait has been selected for through evolutionary time simply because it exists now. "I could argue that hope has had an evolutionary advantage," he says. "It helps us reach our goals and, if we do, then we survive and propagate. The problem is, I can't test that. It's reconstructed history in which you go back and write a tale of what happened. That can be entertaining, but it's simply not an approach from which you can make strong inferences."

To the Buss contention that an absence of jealousy indicates a lack of love, Snyder counters that "it might, instead, suggest a sufficiently independent sense of self that one has the freedom not to be defined by a relationship to another."

In one study, Buss found that 67 percent of husbands and 69 percent of wives would find a serious affair an "irreparable breach." What stuns Buss is "that nearly a third of the sample professed that they would not seek divorce" after a revelation of such an affair. "Who," he wonders, "are these forgiving souls?"

Answers Snyder: "They are the ones who are not self-righteous, not tied to ruminating about how another has wronged them. Their lives are about acknowledging people's fallibility, giving them another chance and not being bitter about transgressions."

Snyder and the Zen Buddhists may agree that jealousy is a dragon in paradise—but that won't stop Buss. He will no doubt continue to argue, as he does in his book's final chapter, for the "potential benefits" of jealousy.

Attempts to rouse jealousy in a partner can serve several purposes, Buss writes. He cites a study of 150 heterosexual California couples in which 38 percent of the women who'd tried to make partners jealous did so to increase the partners' commitment. Forty percent reported evoking jealousy to test the strength of the bond. Inducing jealousy can even ignite sexual passion. Writes Buss: "Clinical cases ... testify to the increased ardor following a bout of jealousy."

Most people will find a measure of relief and a dab of permission in the research that Buss deploys to make his argument. We may hope that most people can also find ways to forgive and forget.—Roger Martin, Center for Research, University of Kansas