Group polarization as conformity to the prototypical group member

Self-categorization theory hypothesizes that group polarization arises from an intragroup process of conformity to a polarized in-group norm (i.e., a norm more extreme than the mean of members' initial opinions but in the same direction). Whether the prototype and the mean coincide depends on whether group responses are moderate or extreme in terms of the comparative social context. A computer simulation (Study 1, N = 1,000 5-person groups) and 2 semi-naturalistic group discussion studies (Study 2, 157 undergraduates assigned to 32 groups; Study 3, 181 university students assigned to 44 groups) were conducted to test this analysis. Results show significant correlational support for the hypothesis that in-group prototypes become more polarized as the group becomes more extreme in the social context