ISSN : 1229-0653
Two experiments were conducted to test three related hypotheses: (1) that simple information on public opinion will change people's attitudes, (2) that information on college student ingroup's social support will have greater effects on the students' attitude change than information on general public's support, and (3) that perceived ingroup norm will be more polarized than actual ingroup norm because of the expected comparison of the students with the general public. The independent variable was the kinds of information on public opinion: (1) ingroup minority/general minority support, (2) ingroup majority/general minority support, (3) ingroup minority/general majority support, or (4) ingroup majority/general majority support conditions. The primary dependent variable was attitude change scores; furthermore, the difference between perceived and actual ingroup norms was additionally analyzed in terms of the degree of polarization. As a result, the first two of the above three hypotheses were supported by data; but the third hypothesis based on self-categorization theory(Turner et al., 1987) was rejected. Thus, it can be said that although perceived ingroup norm was not polarized, external information on public opinion (expecially on ingroup's dominant opinion) in fact changed students' attitudes in the direction of expressed ingroup opinion.