According to the "acting White" hypothesis, African American students who do well in school are negatively sanctioned by their peers, leading them to withdraw future academic engagement. No study to date has tested the entire causal process posited by the hypothesis. This article uses the Education Longitudinal Study of 2002, nationally representative data, to test the process on high school students. The results lend no support to the process predicted by the "acting White" hypothesis for African American students, but they do show that African American students receive lower academic "payoffs" from their socioeconomic status than do White students. Suggestions for future research and reasons for the persistence of the popularity of the acting White hypothesis, despite the dearth of empirical support, are discussed. (Contains 3 tables and 1 figure.)