The role of differentiation between groups and social identity in stereotype formation

Stereotypes are thought to serve a variety of functions for the social perceiver (for reviews see Ashmore and Del Boca 1981; Snyder and Miene 1994; Stangor and Ford 1992; Stroebe and Insko 1989). One basic function of stereotypes is to simplify the process of understanding others by providing information about individuals based on group membership. Stereotypes thus reduce the amount of information in the social environment, obviating the need for effortful processing of interpersonal information (e.g., Allport 1954; Fiske and Taylor 1991; Hamilton and Trolier 1986).

Recently, it has been argued that the informational value of stereotypes extends beyond providing a shortcut or substitute for processing interpersonal information. That is, stereotypes provide an informative, meaningful way of understanding social groups as something more than simply a collection of individuals (e.g., Oakes, Haslam, and Turner 1994; Oakes and Turner 1990). In this way, stereotypes "enrich" rather than merely simplify social understanding (Fiske 1993:165; Leyens, Yzerbyt, and Schadron 1994).

The Role of Differentiation between Groups in Stereotype Formation

Stereotypes are believed to have informational value insofar as they clearly differentiate people on the basis of group membership (e.g., Diehl and Jonas 1991; Fiske 1993; Oakes et al. 1994; Stangor and Schaller 1995; Turner 1987). Diehl and Jonas (1991), for instance, found that traits maximizing distinctiveness between groups facilitated inductive judgments made about an individual's category membership based on knowledge of that individual's traits.

Because stereotypes may often serve such an informational function, one may expect that the goal of differentiating groups motivates the process of stereotype formation. In support of this hypothesis, research by Haslam, McGarty, and Brown (1996) suggests that the illusory correlation effect in stereotype formation (Hamilton and Gifford 1976) is actually caused by an attempt to differentiate groups in a meaningful way rather than by a tendency to overestimate the association between highly distinctive stimuli. Furthermore, Ford and Stangor (1992) demonstrated that as people formed stereotypes of newly encountered groups, attribute dimensions denoting large differences between groups or low variability within groups became more strongly associated with those groups than did dimensions denoting smaller between-group differences or greater within-group variability. These findings suggest that qualities which enhance the value of a trait for differentiating between groups contribute to making that trait stereotypical in the...