Presidential Symposium: Biology and Behavior

J. Michael Bailey presents research on the biological psychology of seuality during the Presidential Symposium. The New Biological Bases of Behavior Henry L. Roediger, III, chair Washington University in St. Louis Presenters J. Michael Bailey Northwestern University Julie Fiez University of Pittsburgh David Buss University of Texas at Austin

For his Presidential Symposium, outgoing APS President Henry L. Roediger, III looked toward the future of psychology. What he saw was a land where brain and behavior are not mutually exclusive, where science fiction converges marvelously into science fact.

The symposium “The New Biological Bases of Behavior” included three speakers at the forefront of this exciting new vision: J. Michael Bailey, Northwestern University; Julie Fiez, University of Pittsburgh; and David Buss, University of Texas at Austin. Bailey studies the biological psychology of sexuality; Fiez, the role of functional neuroimaging in behavioral research; and Buss, the empirical side of evolutionary psychology. To Roediger they represented “the exciting new things which fascinate me but which are not part of my own research and experience.”

It’s easy to be fascinated with Bailey, whose work on sexual orientation attracts controversy the way “Queer Eye for the Straight Guy” attracts ratings. He has drawn more attention lately from the political controversy over the legitimacy of gay marriage, and some organizations hound Bailey with the belief that homosexuality is a non-genetic problem that can be cured.

But you won’t catch Bailey engaged in a nature vs. nurture debate. He believes firmly in biological psychology: “Most psychological traits run in families, and they do so for genetic rather than environmental reasons,” Bailey said. “In general, when siblings resemble each other, when children resemble their parents, it’s for genetic reasons.”

Through twin studies and gender nonconformity research — research on children who exhibit traits of the opposite sex — Bailey arrived at the admittedly tentative conclusion that androgen action during prenatal life dictates whether a child will become “androphilic” (attracted to women) or “gynophilic” (attracted to men). Even in monozygotic, or identical twins, Bailey said it’s not uncommon for a sexually oriented discordance to emerge. “Mothers saw these differences emerge on their own by the age of two,” he said. “They didn’t give Barbies to one and footballs to the other.”

The genetic argument has been bolstered by cases involving accidental castration of newborns who are then raised as girls. Bailey has found that in concordance with their hormonal affiliation and not their sex of rearing, “almost all of these [boys] as adults are attracted to females.”

While much of Bailey’s research focused on homosexuals, he is actually trying to explain the entire sexuality continuum. “If there’s a gene for homosexuality then there necessarily is a gene for heterosexuality,” he said. He hopes that as understanding of the genome grows, he can find a gene that gay brothers share more prevalently than discordant or heterosexual brothers.

Neuroimaging May Stimulate Research

Fiez uses the relatively new technique of functional neuroimaging to link behavior to neural processes. She gives subjects a particular task and presents them with stimuli while monitoring changes in their brains. The tasks cause localized changes in the brain regions being used, and these changes lead to fluctuations in brain blood flow, which are measured using a PET or MR scanner. Measuring these changes provides Fiez an understanding of how neurological workings confirm or disconfirm her behavioral expectations.

Julie Fiez talks about the role of functional neuroimaging in behavioral research.

“Neuroimaging may provide a novel source of data that can help provide novel constraints and perspectives on theoretical models, and give us a new way to investigate the relationship between behavior and brain activity,” she said.

Fiez studies working memory, which she called “the mind’s scratch pad — somewhere to store information and then manipulate it.” To test the limitations of working memory, Fiez asks subjects to remember items while hearing irrelevant auditory effects, such as other words or sounds, designed to disrupt the task. With the help of neuroimaging, Fiez can measure the many areas of the brain activated as the tasks are performed. The result is data that has the theoretical foundation of behavioral psychology with the gravitas of empirical research.

The Evolution of Sexuality

A leading researcher on how human mating strategies lead to sexual conflict, Buss has his own, slightly different pictures of what’s on the brain. He also has a few theories that are likely to make even the most professional scientist blush.

David Buss discusses evolutionary psychology. “Men and women differ solely in those domains where they’ve recurrently faced different adaptive problems over history,” he said.

“The evolutionary metatheory of sex differences is quite straightforward,” Buss said. “Men and women differ solely in those domains where they’ve recurrently faced different adaptive problems over history.” While this means men and women still eat, thermoregulate, and avoid predators with relative similarity, conflict arises over the differences they face. The most obvious are each sex’s reproductive functions, and the minimum obligatory investment in reproduction for males and females. For women, this investment is at least nine months; for men, Buss argued it’s as small as “five minutes, two minutes, or two seconds.”

The difference in obligation results in the continual struggle for commitment on the female end and intercourse on the male end, something Buss called “a perpetual coevoluationary arms race.” Males have adapted deceptive strategies to get women to mate, which includes deceiving women about the depth of their feelings to achieve intercourse. In turn, women have cultivated counter-strategies to delay consent. One such strategy is giving hints of sex in order to extract certain things from men, such as resources, commitment, or favors. Buss offered empirical evidence that something as simple as a smile causes men to infer sexual interest. This sexual overperception bias gives women great leverage in the evolutionary battle. “When a women drops off her car at the mechanic, and she smiles at him, she is not intending to have sex with him,” Buss said. “But if it increases the probability in the male mind from 0 to 2 percent, it probably is worth giving her better care for her car.”

Regardless of what strategies they may employ, biology and psychology have emerged as bedfellows with a future that promises more bliss than divorce.