Dramatic forms of discrimination, such as lynching, property destruction, and hate crimes, are widely understood to be consequences of prejudicial hostility. This article focuses on what has heretofore been only an infrequent countertheme in scientific work on discrimination-that favoritism toward ingroups can be responsible for much discrimination. We extend this counterthesis to the strong conclusion that ingroup favoritism is plausibly more significant as a basis for discrimination in contemporary American society than is outgroup-directed hostility. This conclusion has implications for theory, research methods, and practical remedies.