Effects of the Difference in the Amount of Group Preferential Information on Illusory Correlation

Abstract

This article examined the effects of the difference between the amount of information preferential to Group A (A+ minus A-) and information preferential to Group B (B+ minus B-) on illusory correlation. In Experiment 1, participants rated Group A (majority) more positively and Group B (minority) more negatively in the condition in which the difference in the amount of preferential information between the groups was larger, even when the distinctiveness of the infrequent information of the minority group was the same. Furthermore, illusory correlation in the frequency estimation and cued-recall tasks was found to be more significant in the larger difference condition. In Experiment 2, greater cognitive load did not increase illusory correlation given that the difference in the amount of group preferential information was equal. In Experiment 3, even when the exact ratio of desirable to undesirable behaviors of both groups was completely made known through a summary table, participants made differential group evaluations based on the difference in the amount of group preferential information. Such results imply that the difference in the amount of group preferential information serves as the minimum requirement in the formation of differential impressions of groups in an illusory correlation paradigm.