Abstract
In this article, I want to draw attention to one strand ofthe complex web of processes that are involved when people group others, including themselves, into social categories. I will focus on the tendency to treat members of one's own group more favorably than nonmembers, a tendency that has been called ingroup favoritism. The structure of the article has three parts. First I will offer anevolutionary argument as to why ingroup favoritism, or something very much like it, is required by theories of the evolution of altruism. I will then review some of the basic social psychological research findings dealing with social categorization generally, and ingroup favoritism specifically. Finally, I will examine two problems in business ethics from the point of view of ingroup favoritism to suggest ways in which social psychological principles and findings may be mobilized to help solve problems of racial or gender discrimination in business contexts.
