Concept and first experiment
Research on social identity theory and the minimal group paradigm showed that simply dividing people by a single criterion produces ingroup favoritism. Deschamps and Doise (1978) further divided girls and boys into a red group and a blue group, so that gender and color groups crossed. Gender bias was then smaller than when only one criterion was present. They explained that because a person who is an outgroup member on one criterion is an ingroup member on the other, differences between groups become less salient and differences within groups more salient.
Evaluation patterns
Crossing two categories produces four kinds of people: double ingroup members who share both categories, two kinds of partial ingroup members who share one, and double outgroup members who share neither. Crisp and Hewstone (1999) and Urban and Miller (1998) concluded that evaluations follow several patterns. In the most common additive pattern, double ingroups are rated best, double outgroups worst and partial ingroups in between. When one category matters more, a hierarchical pattern following only that category appears, and there is also a pattern of singling out double outgroups for rejection. Migdal and colleagues' (1998) meta-analysis showed that crossed categorization generally reduces bias but that bias against double outgroups remains.
Multiple categorization and bias reduction
Brewer and colleagues (1987) showed in the field that among Hong Kong schoolchildren social distance varied when categories such as ethnicity and language crossed. Crisp and colleagues (2001) reported that having people think of others in terms of two or more diverse categories at once reduced bias compared with a single category. Crisp and Hewstone (2007) concluded that the more categories there are, the more people come to see others as individuals rather than category members, which can weaken prejudice. Together with the common ingroup identity model, this approach is used as a prejudice-reduction strategy that blurs a single conflict boundary.
FAQ
- What is crossed categorization in simple terms?
- When criteria such as gender and nationality overlap, a person can be "one of us" on one criterion and "one of them" on another.
- Why can it reduce prejudice?
- Compared with dividing people by one criterion, the "us versus them" boundary blurs and people come to see others as individuals rather than categories.
Sources reviewed: 2026-10-26
References
- Deschamps, J.-C., & Doise, W. (1978). Crossed category memberships in intergroup relations. In H. Tajfel (Ed.), Differentiation Between Social Groups (pp. 141–158). London: Academic Press. The original demonstration that crossed categories reduce bias.
- Brewer, M. B., Ho, H.-K., Lee, J.-Y., & Miller, N. (1987). Social identity and social distance among Hong Kong schoolchildren. Personality and Social Psychology Bulletin, 13(2), 156–165. A field study of crossed ethnicity and language in Hong Kong.
- Migdal, M. J., Hewstone, M., & Mullen, B. (1998). The effects of crossed categorization on intergroup evaluations: A meta-analysis. British Journal of Social Psychology, 37(3), 303–324. A meta-analysis of crossed categorization effects.
- Urban, L. M., & Miller, N. (1998). A theoretical analysis of crossed categorization effects: A meta-analysis. Journal of Personality and Social Psychology, 74(4), 894–908. A meta-analysis comparing evaluation pattern models.
- Crisp, R. J., & Hewstone, M. (1999). Differential evaluation of crossed category groups: Patterns, processes, and reducing intergroup bias. Group Processes & Intergroup Relations, 2(4), 307–333. Patterns of evaluating crossed category groups.
- Crisp, R. J., Hewstone, M., & Rubin, M. (2001). Does multiple categorization reduce intergroup bias? Personality and Social Psychology Bulletin, 27(1), 76–89. Tests whether multiple categorization reduces bias.
- Crisp, R. J., & Hewstone, M. (2007). Multiple social categorization. Advances in Experimental Social Psychology, 39, 163–254. A comprehensive review of multiple social categorization.