I Know You Are, But What Am I? Self-Evaluative Consequences of Judging in-group and out-group members, Journal of Personality and Social Psychology
When judging another person, people often spontaneously compare this person with themselves. Six studies examined the self-evaluative consequences of such spontaneous comparisons with in-group versus out-group members. They demonstrate that spontaneous comparisons with in-group members primarily involved the activation of specific individuating knowledge about the self. In particular, knowledge indicating that the self is similar to the judged target was rendered accessible. As a consequence, subsequent self-evaluations that were based on the implications of accessible self-knowledge were assimilated toward in-group targets. Spontaneous comparisons with out-group members, however, primarily involved the activation of more general category knowledge about the self. Specifically, knowledge about judges' membership in a group that distinguished them from the target was rendered accessible. Consequently, self-evaluations were contrasted away from out-group targets.
Thomas Mussweiler, Galen Bodenhausen
Mussweiler, Thomas, and Galen Bodenhausen. 2002. I Know You Are, But What Am I? Self-Evaluative Consequences of Judging in-group and out-group members. Journal of Personality and Social Psychology. 82(1): 19-32.