The ‘Black Sheep Effect’: Social Categorization, Rejection of Ingroup Deviates, and Perception of Group Variability

In this chapter we review evidence on the ‘black sheep effect’: subjects judge likable ingroup members more positively than similar outgroup members, while judging unlikable ingroup members more negatively than similar outgroup members. We attempt to relate these findings to traditional research on group uniformity (Cartwright Festinger, 1950), and to more recent research on social identity (Hogg & Abrams, 1988), and outgroup homogeneity (Park, Judd, & Ryan, 1991). The general idea is that the black sheep effect operates to preserve a positive social identity. It is an outcome of subjective representations of a normative pressure towards ingroup uniformity.