Social Identity Theory contains two seemingly incompatible predictions regarding the relationship between self-esteem and ingroup bias. The first focuses on low self-esteem as motivation for bias, predicting that low self-esteem individuals exhibit more ingroup bias. The second posits that high self-esteem results from exhibiting bias, thus, high self-esteem individuals exhibit greater bias. A meta analysis examined the relationship between self-esteem and ingroup bias. Additionally, the project examined methodological issues such as the lack of consistency in measurement of self-esteem, artificial dichotomization of self-esteem scores, classification of individuals as low self-esteem, and theoretical considerations such as the use of different ingroup bias strategies and the role of social category salience. Thirty-four studies yielding 102 effect sizes from 6660 subjects were included in the analysis.Results indicated a consistent pattern whereby high self-esteem individuals exhibited more ingroup bias than did individuals with low self-esteem. However, this result was moderated by ingroup bias strategy. When using ingroup bias strategies that required ratings of ingroup superiority, high self-esteem individuals showed more ingroup bias than individuals with low self-esteem. However, when using "indirect" strategies, such as rating groups that the individual did not contribute to, differences between low and high self-esteem individuals were not found. This result leads to the conclusion that both groups exhibit ingroup bias; however, individuals with low self-esteem are limited in the types of bias they exhibit. The pattern of results held for all self-esteem measures except for the Collective Self-Esteem Scale (CSES). No differences between low and high self-esteem individuals were found when scores on the CSES defined self-esteem. These results may however be an artifact of interactions with social identity salience. Methodological shortcomings were found in the definition of low self-esteem. Individuals were most commonly classified as "low self-esteem" based on median splits of self-esteem scores. This strategy resulted in classification of some individuals as low self-esteem despite relatively high self-esteem scores. Results of the current analysis are interpreted as indicating that individual level phenomena such as self-esteem may be predictive of group level behaviors. Implications for social identity theories are discussed.
Intergroup threat and affective polarization in a multi-party system
