Background
Henri Tajfel was a Polish-born Jew who fought in the French army in World War II and was taken prisoner. He survived by concealing his origins, but lost most of his family in the Holocaust. He spent his career asking how ordinary people come to hate other groups. In 1970 at the University of Bristol, he divided schoolboys on trivial grounds, such as a supposed preference for Klee or Kandinsky paintings. They still gave more money to their own group. Some even chose to maximize the gap over the other group rather than their own absolute gain. In 1979 he and his student John Turner published social identity theory to explain why.
Core processes
The theory describes three steps. First, we sort ourselves and others into groups (categorization). Next, we adopt a group as part of who we are (identification). Finally, we feel good when our group compares favorably with others (comparison). This produces in-group favoritism even without a real basis. Members of lower-status groups may leave for another group, redefine the comparison ("we're warmer"), or challenge the hierarchy collectively. The theory extends social comparison theory from individuals to groups. Turner later developed it into self-categorization theory (1987).
Applications
It helps explain sports fandom, political polarization, online "us vs. them" fights fueled by confirmation bias, and stigma and discrimination. In marketing, brand loyalty deepens when consumers make a brand part of their identity, which fits Cialdini's unity principle. Research suggests conflict eases when groups share a superordinate identity or a common goal.
FAQ
- What's the key finding of the minimal group studies?
- Even groups formed on meaningless criteria show in-group favoritism.
- Is in-group favoritism bad?
- It fosters belonging and cooperation, but can slide into discrimination against out-groups.
Sources reviewed: 2026-10-26
References
- Tajfel, H., & Turner, J. C. (1979). An integrative theory of intergroup conflict. In W. G. Austin & S. Worchel (Eds.), The Social Psychology of Intergroup Relations (pp. 33–47). Brooks/Cole.
- Tajfel, H. (1970). Experiments in intergroup discrimination. Scientific American, 223(5), 96–102.
- Hornsey, M. J. (2008). Social identity theory and self-categorization theory: A historical review. Social and Personality Psychology Compass, 2(1), 204–222.