This article presents findings of a study on black students attending selective colleges and universities in the United States. Results of a study by sociologists at Princeton University and the University of Pennsylvania indicate that more than a quarter of the black students enrolled at selective American colleges and universities are immigrants or the children of immigrants. The finding suggests that U.S.-born African-American students are more underrepresented at selective colleges than is commonly thought. The report is likely to add fuel to the debate over affirmative-action. Camille Z. Charles, an associate professor of sociology at Penn who is one of the paper's authors, said in an interview. "If you're a purist"--if you view affirmative action as restitution for the harm done by American slavery and segregation-- "then you'll think that this is not in the spirit of affirmative action," she said. "But if you're a diversity purist, and your idea is to expose everybody to as many different kinds of people as possible, then you'll think this is great."