It’s a dance as old as the human race. At cocktail lounges and church socials, during office coffee breaks and dinner parties-and most blatantly, perhaps, in the personal ads in newspapers and magazines-men and women per-
form the elaborate ritual that precedes an essential part of nearly every life: mating.
More than 90 percent of the world’s people marry at some point in their lives, and it is estimated that a similarly large number of people engage in affairs, liaisons, flings or one-night stands. The who, what, when and where of love, sex and romance are a cultural obsession that is reflected in everything from Shakespeare to soap operas and from Tristram and Isolde to 2 Live Crew.
It all may seem very modern, but a new group of researchers argues that love, American-style, is in fact part of a universal human behavior with roots stretching back to the dawn of humankind. These scientists contend that, in stark contrast to the image of brute cavemen dragging their mates by the hair to their dens, our ancient ancestors-men and women alike-engaged in a sophisticated mating dance of sexual intrigue, shrewd strategizing and savvy negotiating that has left its stamp on human psychology.
People may live in a thoroughly modern world, these researchers say, but within the human skull is a Stone Age mind that was shaped by the mating concerns of our ancient ancestors and continues to have a profound influence on behavior today. Indeed, this legacy influences everything from sexual attraction to infidelity and jealousy-and, as new research reveals, even extends its reach all the way down to the microscopic level of egg and sperm.
These new researchers call themselves evolutionary psychologists. In a host of recent scientific papers and at a major conference recently at the London School of Economics, they are arguing that the key to understanding modern sexual behavior lies not solely in culture, as some anthropologists contend, nor purely in the genes, as some socio-biologists believe. Rather, they argue, understanding human nature is possible only if scientists begin to understand the evolution of the human mind.
Just as humans have evolved specialized biological organs to deal with the intricacies of sex, they say, the mind, too, has evolved customized mental mechanisms for coping with this most fundamental aspect of human existence.
When it comes to sexuality and mating, evolutionary psychologists say, men and women often are as different psychologically as they are physically. Scientists have long known that people typically choose mates who closely resemble themselves in terms of weight, height, intelligence and even earlobe length.
But a survey of more than 10,000 people in 37 cultures on six continents, conducted by University of Michigan psychologist David Buss, reveals that men consistently value physical attractiveness and youth in a mate more than women do; women, equally as consistently, are more concerned than men with a prospective mate’s ambition, status and resources.
Evolutionary psychologists think many of these mating preferences evolved in response to the different biological challenges faced by men and women in producing children-the definition of success in evolutionary terms. In a seminal paper, evolutionary biologist Robert Trivers of the University of California at Santa Cruz points out that in most mammals, females invest far more time and energy in reproduction and child rearing than do males.
Human infants require the greatest amount of care and nurturing of any animal on Earth, and so over the eons women have evolved a psychology that is particularly concerned with a father’s ability to help out with this enormous task-with his clout, protection and access to resources. So powerful is this psychological legacy that nowadays women size up a man’s finances even when, as a practical matter, they may not have to. A recent study of the mating preferences of a group of medical students, for instance, found that these women, though anticipating financial success, were nevertheless most interested in men whose earning capacity was equal to or greater than their own.
For men, on the other hand, reproductive success is ultimately dependent on the fertility of their mates. Thus males have evolved a mind-set that homes in on signs of a woman’s health and youth, signs that, in the absence of medical records and birth certificates long ago, were primarily visual. Modern man’s sense of feminine beauty-clear skin, bright eyes and youthful appearance-is, in effect, the legacy of eons spent diagnosing the health and fertility of potential mates.
Curvaceous figures valued
This concern with women’s reproductive health also helps explain why men value curvaceous figures. A paper by Devendra Singh of the University of Texas at Austin reveals that people consistently judge a woman’s figure not by whether she is slim or fat but by the ratio of waist to hips. The ideal proportion-the hips roughly a third larger than the waist-reflects a hormonal balance that results in women’s preferentially storing fat on their hips as opposed to their waists, a condition that correlates with higher fertility and resistance to disease. Western society’s modern-day obsession with being slim has not changed this equation. Singh found, for instance, that while the winning Miss America has become 30 percent thinner over the past several decades, her waist-to-hip ratio has remained close to this ancient ideal.
Women also appreciate a fair face and figure, of course. And what they look for in a male’s physique also can be explained as an evolved mentality that links good looks with good genes. A number of studies have shown that both men and women rate as most attractive faces that are near the average. The average face tends to be more symmetrical, and, according to psychologist Steven Gangestad and biologist Randy Thornhill, both of the University of New Mexico, this symmetry may reflect a person’s genetic resistance to disease.
Some feminists reject the notion that women should alter physical appearance to gain advantage in the mating game. But archaeological finds suggest that the “beauty myth” has been very much a part of the human mating psychology since the times of our ancient ancestors-and that it applies equally to men.
Far from being immutable, biological mandates, these evolved mating mechanisms in the mind are flexible, culturally influenced aspects of human psychology that are similar to people’s tastes for certain kinds of food. The human sweet tooth is a legacy from a time when the only sweet things in the environment were nutritious ripe fruit and honey, says Buss, whose book “The Evolution of Desire” is due out next year. Today, this ancient taste for sweets is susceptible to modern-day temptation by candy bars, though people have the free will to refrain from indulging it. Likewise, the mind’s mating mechanisms can be swayed by cultural influences such as religious and moral beliefs.
Psychologies of mating
Both men and women display different mating psychologies when they are just playing around as opposed to searching for a lifelong partner, and these mental mechanisms are also a legacy from ancient times. A new survey by Buss and his colleague David Schmitt found that when women are looking for “short term” mates, their preference for attractive men increases substantially. In a recent study, Doug Kenrick and Gary Groth of Arizona State University found that while men, too, desire attractive mates when they’re playing the field, they will actually settle for a lot less.
Men’s diminished concern about beauty in short-term mates reflects the fact that throughout human evolution, men have often pursued a dual mating strategy. The most successful strategy for most men was to find a healthy, fertile, long-term mate. But it also didn’t hurt to take advantage of any low-risk opportunity to sire as many kin as possible outside the relationship, just to hedge the evolutionary bet. The result is an evolved psychology that allows a man to be sexually excited by a wide variety of women even while committed to a partner.
Women’s affairs
Surveys in the United States show that at least 30 percent of married women have extramarital affairs, suggesting that, like men, women also harbor a drive for short-term mating. But they have different evolutionary reasons for doing so. Throughout human existence, short-term flings have offered women an opportunity to exchange sex for resources. In Buss and Schmitt’s study, women value an “extravagant lifestyle” three times more highly when they are searching for a brief affair than when they are seeking a long-term mate. Women who are secure in a relationship with a committed male might still seek out attractive men to secure healthier genes for their offspring. Outside affairs also allow women to shop for better partners.
A woman may engage the sexual interest of several men simultaneously in order to foster a microscopic battle known as sperm competition. Sperm can survive in a woman’s reproductive tract for nearly a week, note biologists Robin Baker and Mark Bellis of the University of Manchester, and by mating with more than one man within a short period of time, a woman sets the stage for their sperm to compete to sire a child-passing this winning trait on to her male offspring as well.
With its emphasis on how both men and women are active players in the mating game, evolutionary psychology holds out the promise of helping negotiate a truce of sorts in the battle of the sexes-not by declaring a winner but by pointing out that the essence of the mating game is compromise, not victory. The exhortations of radical feminists, dyed-in-the-wool chauvinists and everyone in between are all spices for a sexual stew that has been on a slow boil for millions of years. It is no accident that consistently, the top two mating preferences in Buss’ survey-expressed equally by males and females worldwide-were not great looks, fame, youth, wealth or status, but kindness and intelligence.
In the rough-and-tumble of the human mating game, they are love’s greatest allies.
