Social Identity Theory
The account that people sort themselves and others into social categories, take part of their self-description from their groups, and compare their own group with others.
What it is
Henri Tajfel developed it with John Turner, and set it out with him in a 1979 chapter on intergroup relations. It grew from earlier work by Tajfel and Wilkes showing that sorting things into classes makes items within a class look more alike and items in different classes look further apart. Later work extended it into self-categorisation theory.
In effect
In the article on social identity theory, it is the subject itself, traced from a study of judging lines to everyday group loyalty.
What it does not say
It is a theory of how group membership feeds self-description. It does not say that group membership must lead to hostility toward other groups.
Sources
- 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. Brooks/Cole.
- Tajfel, H., & Wilkes, A. L. (1963). Classification and quantitative judgement. British Journal of Psychology, 54(2), 101-114.