Bias in judgment: Comparing individuals and groups.

Abstract

The relative susceptibility of individuals and groups to systematic judgmental biases is considered. An overview of the relevant empirical literature reveals no clear or general pattern. However, a theoretical analysis employing J. H. Davis's (1973) social decision scheme (SDS) model reveals that the relative magnitude of individual and group bias depends upon several factors, including group size, initial individual judgment, the magnitude of bias among individuals, the type of bias, and most of all, the group-judgment process. It is concluded that there can be no simple answer to the question, "Which are more biased, individuals or groups?, " but the SDS model offers a framework for specifying some of the conditions under which individuals are both more and less biased than groups. A great deal of research in social and cognitive psychology has been devoted to demonstrating what is probably an uncontroversial proposition: that human judgment is imperfect. What makes this work interesting and useful is that such imperfections often constitute more than random fluctuations around "rational, " prescribed, or ideal judgments. Rather, humans consistently exhibit systematic biases in their judgments. Some of