Ingroup bias as a function of salience, relevance, and status - an integration

This paper reports the results of a meta-analytic integration of the results of 137 tests of the ingroup bias hypothesis. Overall, the ingroup bias effect was highly significant and of moderate magnitude. Several theoretically informative determinants of the ingroup bias effect were established. This ingroup bias effect was significantly stronger when the ingroup was made salient (by virtue of proportionate size and by virtue of reality of the group categorization). A significant interaction between the reality of the group categorization and the relative status of the ingroup revealed a slight decrease in the ingroup bias effect as a function of status in real groups, and a significant increase in the ingroup bias effect as a function of status in artificial groups. Finally, an interaction between item relevance and ingroup status was observed, such that higher status groups exhibited more ingroup bias on more relevant attributes, whereas lower status groups exhibited more ingroup bias on less relevant attributes. Discussion considers the implications of these results for current theory and future research involving the ingroup bias effect.