Santa Barbara, California -- Leda Cosmides and John Tooby, partners both in life and in scholarship, tend to finish each other’s sentences.
Sometimes he states a premise and she, the conclusion. Or she makes a point and he refines it. Or one of them questions what the other has said, and they skirmish -- frequently interrupting one another in midsentence without breaking stride -- until one prevails and the other retreats, at least temporarily.
Usually they seem satisfied by the exchange.
“We both know things the other doesn’t, so together things get clear that wouldn’t be clear to either of us alone,” says Mr. Tooby, a professor of anthropology at the University of California at Santa Barbara. Ms. Cosmides, his wife since 1979, is an assistant professor of psychology there.
Though hired by different departments, both are apostles of evolutionary psychology, a controversial young discipline that examines human behavior in light of our ancestral beginnings as hunter-gatherers.
One basic tenet is that the brain contains many specialized devices, akin to computer programs, that have evolved over millions of years through natural selection to handle problems faced by hunter-gatherers -- from communicating with others and finding mates, to choosing foods and avoiding predators.
Such adaptations affect all cultures, Ms. Cosmides and Mr. Tooby maintain. They note, for example, that a fear of snakes persists throughout the world, even where the reptiles pose no threat.
The researchers reject the notion that the mind is a blank slate that develops primarily according to a person’s experiences. Rather, they argue, the key to understanding human behavior lies in identifying specific adaptations that have evolved over time.
Along with more than 100 others throughout academe who, they say, are avowed evolutionary psychologists, they hope to “map” as many such aspects of the brain’s architecture as they can.
As co-directors of Santa Barbara’s year-and-a-half-old Center for Evolutionary Psychology, which they established as a clearing-house for information and to help attract grants, the two researchers thus have a mission that spans and challenges both of their disciplines -- and much of traditional social- science thinking -- over how the mind works.
Experience is important to mental development, Ms. Cosmides acknowledges. “The question is, ‘How do you learn? What are the learning programs that allow that to happen?’ Taking an evolutionary approach gives you an idea of what kind of tasks our mind was designed to do.”
She and her husband also share a belief that higher education should do more to encourage the kind of intellectual deference that they show each other. Universities need to become more interdisciplinary, they say, and more accepting of scholars beyond the mainstream.
They’ve had difficulty being accepted themselves, they say, in part because of a misperception that their interest in natural selection and adaptation means that they favor genetic explanations for major racial differences.
In The Adapted Mind: Evolutionary Psychology and the Generation of Culture (Oxford University Press, 1992), which they co-edited with Jerome H. Barkow, the couple deny that their approach points to a genetic basis for “important differences between individuals, races, and classes.” On the contrary, they contend, their work points to a “psychic unity” among all people.
Some scholars say Ms. Cosmides and Mr. Tooby have drawn fire mainly for trying to bridge the unbridgeable: the chasm between biological and behavioral analyses of what makes human beings tick -- nature or culture, genes or the mind. “In order to be accepted in this interdisciplinary area,” says Timothy Perper, a biologist, “you have to worship one god or the other, not both.”
But the two researchers have knowingly tried to have it both ways. And they have explored issues certain to inflame some people -- such as suggestions that women are attracted to dominant men.
Ms. Cosmides and Mr. Tooby also ascribe their troubles -- including several years of frustration in their job searches before connecting with Santa Barbara in 1990 -- to a decision they made early on to be open about their identity as evolutionary psychologists.
“To take the kind of position that we took, the daily experience is having people pull you aside and tell you that they think you are evil,” says Mr. Tooby.
Indeed, he and his wife say their experiences point to one of academe’s biggest shortcomings -- a predilection for in-group- out-group thinking, which is illuminated on a broader plane by findings in evolutionary psychology.
In general, they say, many adaptations that worked for hunter- gatherers involve problems that no longer exist -- or that now seem to call for different responses.
Some of those adaptations relate to coalitional psychology, a research focus of Mr. Tooby. He says there are specialized mechanisms in the mind that divide the world into groups -- an approach that can be seen, for example, in how people deal with ethnic and racial issues.
In higher education, he says, coalitional thinking can lead to the exclusion of some outstanding researchers. “People who are out there doing new and interesting things are, by definition, not members of the tribe,” he explains -- so they don’t get hired.
Ms. Cosmides adds that when scientists pick up a scholar’s research paper, their first question often is, “Is this person attacking me?” or, “Are they attacking my coalition, even if it’s not me?’”
Mr. Tooby observes that while some people see political motivations or, at least, social-policy implications in his and Ms. Cosmides’s work, the two of them are “much more resistant” to reaching such conclusions.
What he and his wife are about, he says, is the pursuit of truth, and eventually researchers in evolutionary psychology will find “a real scientific prize out there: understanding who we are.”