Availability and Formation of Stereotypes

Abstract

Availability refers to the ease with which instances of a particular class of events can be brought to mind and constitutes a potential source of bias in judgments of the size of that class. Bias occurs when the magnitudes of related classes do not correspond to the ease with which instances of those classes can be retrieved from memory. Previous research has indicated that, if events in a class are defined by the co-occurrence of phenomena which are themselves rare, then recall of that class is likely to be facilitated and its magnitude exaggerated. Based on a study by Hamilton and Gifford an experiment was designed in which male and female subjects viewed a series of slides. On each slide an attribution of a desirable or an undesirable trait was made to a member of one of two fictitious groups. The slide set was constructed such that one group had twice as many members as the other; desirable traits were two and one-half times more frequent than undesirable traits, and each group had the same ratio of members with undesirable vs desirable traits. As anticipated, when asked to recall the number of undesirable characteristics attributed to the two groups, subjects significantly overestimated the number of such characteristics which had been assigned to the smaller group. The results are discussed in terms of the concepts of availability and illusory correlations.