Sharing differences: The inductive route to social identity formation

A dominant assumption in social science is that shared similarities are the foundation for social categorization and identification. Accordingly, heterogeneity should hinder social identity formation. This paper argues the opposite can also be true: in heterogeneous groups, strong social identities can be built on expressions of individuality (inductive social identity formation), instead of shared similarities (deductive social identity formation). Two experiments manipulate social identity formation (deductive vs. inductive social identity formation) and support this idea. Study 1 shows that in heterogeneous groups, inductive social identity formation can result in higher identification and perceived entitativity than deductive social identity formation. Study 2 manipulates heterogeneity and confirms that while deduction of a social identity fosters a strong sense of identification in homogeneous groups, in heterogeneous groups a strong sense of identification can be brought about through induction. This pattern is also visible in real within-group cooperation.