The highs and lows of group homogeneity

Two experiments yielded further evidence for the ingroup homogeneity effect (Kelly, C., 1989. Political identity and perceived intragroup homogeneity. Br. J. Soc. Psychol. 28, 239-250; Simon, B., 1992. The perception of ingroup and outgroup homogeneity: reintroducing the intergroup context. In: Stroebe, W., Hewstone, M. (Eds.), Eur. Rev. Soc. Psychol. Vol. 3. Wiley, Chichester; Simon, B., Brown, R., 1987. Perceived intragroup homogeneity in minority-majority contexts. J. Personal. Soc. Psychol. 12, 463-468.). In the first experiment, with the aim of investigating the effect of the context of judgment, we asked psychology students to judge the variability of psychologists or of social workers (one-group conditions) or to judge both groups (two-group condition) on dimensions typical of psychologists and on dimensions typical of social workers. As predicted, whereas an ingroup homogeneity effect was found for the dimensions typical of the ingroup in the two-group condition, no asymmetry in perception of group variability emerged in the one-group conditions. In the second experiment, we examined the effect of ingroup identification in an explicit intergroup situation. In line with predictions, high identifiers perceived greater homogeneity in the ingroup than in the outgroup. In contrast, low identifiers displayed the opposite tendency. The impact of context and social identification on group entitativity is considered in its cognitive and motivational aspects.