Accentuation of information processes and biases in group judgments integrating base-rate and case-specific information

This article investigates differences in the ways that groups and individuals apply information-processing strategies and fall prey to biases in their judgments. Judgments were made on probabilistic inference problems that involved base-rate and case-specific information. Consistent with hypotheses, when individuals neglect base-rate information in their probability judgments, groups accentuate this tendency. Moreover, when the source of case-specific information is inaccurate, individuals neglect the case-specific information, and groups accentuate this tendency with the base-rate information dominating their probability judgments. In addition, groups accentuate the strategies used by individuals to integrate the base-rate and case-specific information. These results provide strong support for a group accentuation tendency for the application of information-processing biases and the strategies used to integrate information. Discussion reflects upon the relationship of the results of this experiment with other research on base-rate neglect and group judgment. Underlying mechanisms and potential moderators of the group accentuation pattern are also discussed.