Cross-categorization effects in intergroup discrimination: Adding versus averaging

In two between-participants experiments (Ns = 216 and 260), Chinese in Singapore rated competence and attractiveness of strangers described (a) by cross-categorizations of race (Malay: our-group vs. Chinese: in-group) and nationality (Malaysian: out-group vs. Singaporean: in-group), (b) by simple categorization of either race or nationality, and (c) by no-group label. An additive effect of cross-categorizations was obtained: Both the race and nationality categorizations produced main effects but no interaction effect. Analyses of variance of the simple and cross-categorization data together also retained the additive effect as predicted by the adding rule. However, the higher ratings of the in-group than of the out-group in both the simple and cross-categorization conditions were based on an out-group derogation instead of an in-group bias. Explanations of the our-group derogation and suggestions for additional work on the cross-categorization effects are discussed.