Scholars spanning the social sciences and humanities wrestle with the complex and often contested meanings of race, racism, and discrimination. In all of this enterprise, sociologists rightly retain a special claim to illuminating processes of group boundary maintenance, systems of racial inequality and supporting ideologies, and attendant patterns of intergroup behavior (Jackman 1994; Lamont 2000). Mainstream sociological research, however, has focused principally on the structural manifestations of race, racism, and discrimination, particularly as they characterize black-white relations (Wilson 1978). Sociologists have made signal contributions to the understanding of modern ghetto joblessness and poverty (Wilson 1996), of racial residential segregation (Massey and Denton 1993), and of fundamental disparities in accumulated wealth (Oliver and Shapiro 1995). In some critical respects this work has expanded to include multiracial and multiethnic comparisons with respect to both key economic (Lichter and Oliver 2000; Smith 2001; Waldinger 1996) and residential outcomes (Charles 2001; Emerson, Yancey, and Chai 2001). To a surprising degree, however, the micro social processes necessarily embedded in these structural analyses are still largely unaddressed. Yet the basic social processes invoked by the terms race, racism, and discrimination are quintessentially social psychological phenomena; sociologists ignore or downplay this basic insight at the discipline's peril. These concepts concern the meanings of social groupings and how those meanings come to guide patterns of relations among individuals recognized as members of particular groups. They immediately entail the labeling and social learning of group categories, identity, feelings, beliefs, and related cognitive structures. These factors, in turn, are expressed in lines of interaction and behavior that flow from, reinforce and reconstitute, or come to transform those social categorizations. In addition, such categorizations have direct implications for the structure and basic conditions of social organization. That is, race,1 racism,2 and discrimination3 are also, and perhaps most fundamentally, bases and mechanisms of hierarchical differentiation that shape the ordering of social relations as well as the allocation of life experiences and life chances (Zuberi 2001a).