Abstract

Two experiments were conducted to test the controversy on the process of group member's attitude formation between two theories about group polarization. Social comparison theory suggests that group member's attitude is compromised between social value and ingroup norm, on the other hand self-categorization theory proposes that it is determined by conformity to ingroup norm. This problem was likely to be solved by comparisons among personal attitude, ideal and estimated ingroup norm, and these comparisons were expected to have different results according to the level of value clearness. Specifically, it was hypothesized that personal attitude would be more desirable than ingroup norm but less desirable than ideal in value-clean condition, and three measures would be no difference in value-unclean condition. The results of experiment 1 which measured attitude on risky-conservative dimension supported the hypothesis only in value-clean condition. But the results of experiment 2 which manipulated general social desirability supported all hypotheses of both condition and showed significant polarization effect in both condition. These results imply that social comparision theory and self-categorization theory have their own condition more suitably applicable.