Perception of out-group homogeneity and levels of social categorization: Memory for the subordinate attributes of in-group and out-group members.

Four experiments were conducted to explore the hypothesis that in-group members perceive their own group as more variegated and complex than do out-group members (the out-group homogeneity principle). The first three experiments were designed to demonstrate this effect in a symmetric manner for both parties of the in-group-out-group dichotomy, and the fourth experiment tested one particular theoretical account of this phenomenon. In Experiments 1 and 2, men and women subjects estimated the proportion of men or women who would endorse a variety of personality/attitude items. The items were constructed to vary on the dimensions of stereotypic meaning (masculinity-femininity) and social desirability (favorable-unfavorable). It was predicted and found that outgroup members viewed a group as endorsing more stereotypic and fewer counterstereotypic items than, did in-group members. These findings were interpreted as support for the out-group homogeneity principle, and it was argued that since this effect was general across items varying in social desirability, the phenomenon was independent of traditional ethnocentrism effects. Experiment 3 asked members of three campus sororities to directly judge the degree of intragroup similarity for their own group and two other groups. Again, each group judged its own members to be more dissimilar to one another than did out-group judges. In Experiment 4 a theory was proposed suggesting that different levels of social categorization are used to encode in-group and out-group members' behavior and that this process could account for the perception of out-group homogeneity. It was predicted and found that men and women were more likely to remember the subordinate attributes of an in-group member than of an out-group member, which provides some evidence for the theoretical model.