We propose that hypodescent—the assignment of mixed-race individuals to a minority group—is an emergent feature of basic cognitive processes of learning and categorization. According to attention theory, minority groups are learned by attending to the features that distinguish them from previously learned majority groups. Selective attention creates a strong association between minority groups and their distinctive features, producing a tendency to see individuals who possess a mixture of majority- and minority-group traits as minority-group members. Two experiments on face categorization, using both naturally occurring and manipulated minority groups, support this view, suggesting that hypodescent need not be the product of racist or political motivations, but can be sufficiently explained by an individual’s learning history.