Categorization by groups and individuals

Categorization is a core psychological process that is central to decision making. While a substantial amount of research has been conducted to examine individual categorization behavior, little is known about how the outputs of individual and group categorization may differ. Four experiments demonstrate that group categorization differs systematically from individual categorization in the structural dimension of category breadth: categorizing the same set of items, groups tend to create a larger number of smaller categories than individuals. This effect of social context is a function of both taskwork and teamwork. In terms of taskwork, groups’ greater available knowledge mediates differences in category breadth between individuals and groups by increasing utilized knowledge (study 2). In terms of teamwork, task conflict moderates the effect of social context on category breadth (study 3). Moreover, the experience of categorizing individually or in a group influences individuals’ subsequent judgments (study 4).