Minimal but meaningful: Probing the limits of randomly assigned social identities.

The current studies (total N = 151) experimentally manipulated meaningfulness in novel social groups and measured any resulting ingroup biases. Study 1 showed that even when groups were arbitrary and presumptively meaningless, 5- to 8-year-old children developed equally strong ingroup biases as children in more meaningful groups. Study 2 explored the lengths required to effectively reduce ingroup biases by stressing the arbitrariness of the grouping dimension. Even in this case, ingroup bias persisted in resource allocation behavior, although it was attenuated on preference and similarity measures. These results suggest that one needs to go to great lengths to counteract children's tendency to imbue newly encountered social groups with rich affiliative meaning.