Over the years, scholars have put forth all sorts of theories to explain the persistent achievement gap between blacks and whites in college. A new study by a team of Penn sociologists has now put those theories to the statistical test.

Assistant Professor of Sociology Camille Zubrinsky Charles and former Professor of Sociology Douglas Massey (now at Princeton) have spent the past four years surveying more than 3,900 undergraduates at 28 highly selective colleges and universities across the country, including Penn. Their study, the National Longitudinal Survey of Freshmen (NLSF), examines what students of various racial, ethnic and socioeconomic backgrounds bring to college with them and what they get out of their time there.

The first fruits of their study were released this summer with the publication of “The Source of the River” (Princeton, 2003). In their book, Massey, Zubrinsky, postdoctoral fellow Garvey Lundy and sociology doctoral student Mary Fischer unpack the personal baggage freshmen carry with them to college—socioeconomic, cultural, academic, social and attitudinal—and relate it to their college experience during their first year.

What they found lends credence to two theories that attempt to explain the performance gap: the theory of capital deficiency and the stereotype threat theory.

The first holds that lack of financial, emotional and intellectual investment is to blame for the performance gap. The second argues that minority students do worse on tests when they believe their ability is being measured.

“We found that the theories of capital deficiency were important” in accounting for student performance, Charles said. “Lack of financial resources or educated parents made a difference.” In fact, she noted, black students in elite colleges showed more socioeconomic diversity and were on the whole less affluent and more likely to live in segregated communities than their white counterparts. Those who grew up in integrated communities and attended predominantly white schools did as well as their white counterparts in college.

Furthermore, “the students who showed vulnerability to stereotype threat got lower grades and were more likely to drop out of school. We think this is the first time anyone was able to document that using survey data.”

Charles and her colleagues also found that black students devoted no less time to their academic work than other students did. But they did feel a need to do things that gave them a sense of comfort in a campus culture they perceived as hostile on top of their studies and extracurricular activities.

What suffered, she said, was sleep. “They’re sleeping, on average, four hours less per week, and that can be huge in terms of being productive.”

Charles argues that affirmative action is worth preserving for the benefits it confers on both the students and society as a whole, and her book serves as a complement to Derek Bok and William Bowen’s book “The Shape of the River,” which defends affirmative action. She stresses the need to transform the institutional climate so minority students can live up to their potential.

The authors are currently at work on a second volume containing the results of the complete longitudinal study, which concluded this year.