Outlines present conceptualizations of stereotypes in psychology, and discusses theoretical approaches linking ethnic stereotypes to negative attitudes and discriminatory behavior. Research results concerning the content of ethnic stereotypes, their development and resistance to change, and the reciprocal nature of intergroup stereotypes are reviewed. Several critical issues, E.g., methodological problems and the “kernel of truth” controversy, are also discussed. It is suggested that none of the current definitions of stereotype are completely adequate. It is proposed that much of the ambiguity, both conceptual and empirical, in this area may be reduced if stereotypes are regarded as generalizations that are considered as unjustified by the person who affixes the label. There are several types of criteria under which a generalization may be considered unjustified.