There are large racial disparities in school discipline in the United States, which, for Black students, not only contribute to school failure but also can lay a path toward incarceration. Although the disparities have been well documented, the psychological mechanisms underlying them are unclear. In two experiments, we tested the hypothesis that such disparities are, in part, driven by racial stereotypes that can lead teachers to escalate their negative responses to Black students over the course of multiple interpersonal (e.g., teacher-to-student) encounters. More generally, we argue that race not only can influence how perceivers interpret a specific behavior, but also can enhance perceivers’ detection of behavioral patterns across time. Finally, we discuss the theoretical and practical benefits of employing this novel approach to stereotyping across a range of real-world settings.