Men, women and Darwin

THREE years ago, Robert Kurzban spotted an advertisement for a service called HurryDate, offering an evening of three-minute meetings with 25 potential dates.

Kurzban was intrigued — but not because he was looking for romance. As an evolutionary psychologist at the University of Pennsylvania, he thought speed dating could afford him a rare chance to study how people behave in real dating situations.

With the agreement of the company, Kurzban and a colleague surveyed the HurryDaters about a range of topics including religious background and their desire for children. Their fundamental questions: Did participants select the people most like themselves? Or did most of them prize similar traits — such as appearance or high income — and try to get the best deal they could in the mating market?

What the researchers discovered was that men and women chose their dates on the basis of "generally agreed upon mate values," the mating market hypothesis. Another finding: Both sexes relied mainly on physical attractiveness, largely disregarding factors such as income and social status.

"HurryDate participants are given three minutes in which to make their judgments," the psychologists wrote in a paper published in the May issue of the science journal Evolution and Human Behavior, "but they mostly could be made in three seconds."

The HurryDate research is one example of the everyday applications of evolutionary psychology, an interdisciplinary field that is influential and controversial. Other recent studies of human mating have explored issues such as the male preference for dating subordinates, why women have extramarital affairs and what trade-offs both sexes are willing to make in choosing partners.

Evolutionary psychology sees the mind as a set of evolved psychological mechanisms, or adaptations, that have promoted survival and reproduction. One branch of evolutionary psychology focuses on the distinct mating preferences and strategies of men and women. For example, because our male ancestors were easily able to sire numerous children at little cost to their fitness, the theory says, they were inclined to short-term mating with multiple partners. In choosing mates, they gravitated toward youth and physical attractiveness — markers of fertility and health.

By contrast, females, for whom conception meant pregnancy and the need to care for a child, were more selective, searching for long-term commitments from males with the resources and willingness to invest in them and their offspring.

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Theory's evolution

Support for this theory came from a landmark study by psychologist David M. Buss and colleagues in the 1980s, involving 37 cultures and 10,047 individuals. Buss, now professor of psychology at the University of Texas in Austin, found marked similarities across cultures, including a female preference for men with resources and status that persisted even when women had considerable resources of their own. Overall, women valued financial resources in a mate twice as much as men did.

"Up until that time, everyone believed that these things were very tethered to individual cultures and that cultures were infinitely variable," said Buss, whose more recent books have described the utility of jealousy and the universality of homicidal impulses.

Buss' survey continues to influence research on human mating. But some scientists and social scientists remain skeptical, saying evolutionary psychologists tend to neglect the role of learning and culture and to overemphasize genetics. Melvin Ember, an anthropologist and president of the Human Relations Area Files, a Yale-affiliated research organization, says that "focusing on universals" fails to explain either individual or cultural variation.

Jaak Panksepp, a neuroscientist at Falk Center for Molecular Therapeutics at Northwestern University, has chided evolutionary psychologists for ignoring recent neurological findings about human and mammalian brains.

Despite the objections, the field of evolutionary psychology is growing.

In recent years, Darwinian feminists and others have developed a more nuanced view of the complexities of female behavior. Women, it seems, aren't quite as monogamous as their partners might wish. They too sometimes pursue short-term mating strategies, though not everyone agrees on why.

Randy Thornhill, professor of biology at the University of New Mexico, said he has discovered that women, in an unconscious bid for better genes, will choose "extra-pair copulation" — that is, have affairs — with men who are more attractive (though perhaps less likely to commit) than their long-term mates. Other research indicates that women make different choices at different points in their menstrual cycle, opting for better-looking, more symmetrical and more masculine-appearing men when they are at their most fertile.

In short-term relationships, physical attractiveness is a priority for women, just as it is for men, according to a study by psychologists Norman P. Li and Douglas T. Kenrick that is slated to appear sometime next year in the journal of Personality and Social Psychology.

Trying to draw a distinction between "luxuries" and "necessities," the researchers gave men and women varied "mating budgets" and, in a series of tests, asked them to construct their ideal mate, using such qualities as looks, social status, creativity, and kindness. For one-night stands and affair partners, both women and men sought physical attractiveness above all else.

For long-term mates, the expected sex differences emerged: Men kept preferring attractiveness, and women opted for social status, as well as warmth and trustworthiness. But after their minimum requirements for these necessities were met, both sexes chose well-rounded partners over those with the very best looks or the highest status.

In other words, "Men are not complete pigs, and women are not complete gold-diggers," said Li, assistant professor of psychology at the University of Texas at Austin.

This makes good evolutionary sense, considering that to father a child, Li said, "you don't need the most beautiful woman in the world." At the same time, women "don't need the richest man in the world to guarantee reproductive success. You just need somebody who's not a bum, basically."

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Trading up

In practice, Li said, people's budgets in the mating market are determined by what they themselves have to offer. "So a guy who is extremely high status or very wealthy can trade up for a more physically attractive partner," he said. And "women trying to make themselves more physically attractive so they can get a higher quality mate are not completely misguided."

It is also true, Li said, that very smart and successful women will have a harder time finding partners. "It seems that men want somebody intelligent enough so that they can recognize the man's brilliance," he said, "but not necessarily enough to challenge them — or so smart that they find someone else more interesting."

John Marshall Townsend, professor of anthropology at the Maxwell School at Syracuse University, says that women's status requirements often complicate their search for a mate. Townsend showed a group of female medical students, law students and professionals pictures of men dressed in different ways — wearing, for instance, a fast-food uniform or a designer suit and Rolex watch. He also gave participants descriptions of each man's social status.

The results were decisive. "Here's Mr. Hottie, but if he's in the wrong costume, and given the wrong status description, then she won't go out with him, much less go to bed with him or marry him," said Townsend. "You could put Cary Grant in a Burger King outfit, and he looks dorky."

If women do occasionally date "down" in terms of social status, Townsend said, "that would be out of desperation."

By contrast, he says, men are likely to date any physically attractive woman. When it comes to marriage, "guys are not completely insensitive to social class," but, he said, they're "not looking for socioeconomic gain."

Another recent study, by Stephanie L. Brown of the University of Michigan's Institute for Social Research and Brian P. Lewis of Syracuse University in New York, suggested that men prefer long-term relationships with subordinates rather than co-workers or supervisors. By contrast, women showed no significant preference for socially dominant men.

The reason for this result, Lewis hypothesized, is that men think they would "have more control over the behavior" of female subordinates, including being able to ensure female monogamy, and thus the paternity of any children. "Female infidelity is a severe reproductive threat to males only when investment is high," as it is in long-term relationships, the authors write.

Some evolutionary psychologists think gender differences can be overstated. In "The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature," Geoffrey Miller suggests that the human mind evolved, much like the elaborate peacock's tail, primarily as a way of attracting partners of both sexes. His book argues that traits such as musical and artistic ability played no clear role in helping human beings survive, but instead enhanced their reproductive success.

For Miller, assistant professor of psychology at the University of New Mexico, intellect and creativity are, well, sexy. "Guys are not picky about short-term mating, which is why we don't read about IQ scores in Penthouse magazine," he said. But when it comes to long-term relationships, he said, "There's good evidence that guys are as picky as women about the mental traits of partners."

In the context of speed dating, where quick impressions count, HurryDate president Adele Testani says she was not surprised to learn that both sexes were most choosy about physical attractiveness. Although participants invariably ask each other about their careers, Testani said, "it really is all about that face-to-face chemistry and connection and attraction." She added: "You're certainly not going to find out if you're going to marry the person" in a few minutes.

Kurzban said the "rich visual information" supplied by HurryDate encounters may help men and women get over the first hurdle of appearance, before other factors, such as social status, become relevant.

In the end, said Li, men and women tend to strive for the best partner their own attributes can buy. "Falling in love," he said, "is basically a process where both sides feel they're getting a good deal."

latimes.com : Health