Imagine pressing the rim of a five-inch vial to your mouth, pursing your lips, and letting saliva bubble forth into a test tube.

For Alicia Breakey ’08, no imagination is needed. The self-identified “spit-girl,” Breakey has recently begun collecting saliva samples from the Yale debate team for her senior research project in biological anthropology. She laughs fondly as she describes her initial battery of tests in early October: at first, many debaters kept trying to spit into the vial from a distance, as if they were trying to lob phlegm onto the sidewalk. But after a few primers in drooling technique, the team quickly caught on. Since then, the subjects have become enthusiastic. One student filled a tube with enough spit to “float a small boat,” notes Breakey. Another rushed up to her after depositing a sample and asked to be allowed to spit again. “They were having such a blast,” Breakey recalls warmly. Watching her excitement as she discusses her project — her “baby” — it becomes clear that she’s having a blast too.

Breakey’s study, advised by professors Richard Bribiescas and Stephanie Anestis, tests the effect of competition on testosterone levels in male and female debaters. In her field research, Breakey first collects spit samples on days on which there aren’t competitions. Then she establishes her subjects’ baseline testosterone levels by running assays at the Human and Primate Reproductive Ecology Lab. As she travels with the team, she solicits saliva just before and soon after each debating round, attaching a survey to each sample in which competitors predict their rhetorical success.

Breakey expects her findings about men to correlate with preexisting research. Earlier studies of men involved in contests ranging from baseball to chess have shown a rise in testosterone levels as subjects anticipate competition, with higher post-game levels in winners than in losers. This pattern supports larger evolutionary theories: since males have evolved to compete for mates, more testosterone in winners would encourage future competition and accordingly promote reproductive success.

The results for women, where experiments have been few and inconclusive, might be more interesting. Breakey’s hypothesis is that female winners and losers will not exhibit large swings in testosterone depending on performance; such differences, she claims, would not serve an adaptive function in women to the degree they do in men. Without tests of alleged sex discrepancies, evolutionary theories, Breakey laments, will become “just-so stories.”

Studying women isn’t the only way Breakey’s experiment is significant. Although she claims her study is neither groundbreaking nor innovative, her advisor Stephanie Anestis is quick to differ. “Alicia’s study is very original,” she says. Testing the debate team eliminates the confounding hormonal impact of strenuous physical activity while still ensuring that the subjects care about the competition. Equally compelling is the fact that the winner and loser of each debate round are not announced until the next day, so testosterone levels measured after the match are related to the perception, not the reality, of having won or lost.

Other aspects of the study are noteworthy not for their originality but for their connections to the fundamentals of biological anthropology, a subject that bridges the social and natural sciences. On the one hand, the discipline is a science based on experimentation and chemical analysis. While Breakey jokes that the rows of white coats hanging in the lab are just for show, Paul Morse ’08, one of only three senior majors in the department, acknowledges that “there is a stage [in biological anthropology research] when you’re that person in a labcoat.” But he also says, on the other hand, that working with human subjects links the field to its roots in social theory. Breakey agrees that societal factors are crucial to contextualizing her findings: she is careful to examine the culture from which her data arises and not to extrapolate her results from women on an Ivy-league debate team to the gender as a whole.

As Breakey characterizes herself (in the ’08 system) as a “group 3 1/2 major,” it becomes clear the study’s ambiguity is a good thing. With a chance to cross disciplines, talk about sex, and get people to spit for you, anthropology on Science Hill has never looked more appealing.