Effects of background knowledge on category construction

In category construction, participants are commonly asked to sort items into 2 groups. Although natural categories have a family resemblance (FR) structure, participants rarely construct FR categories in the sorting task. In previous research, participants constructed FR categories when the features of the instances could be integrated into a coherent category, if the category theme was provided. In Experiments 1-4, participants constructed more FR categories with thematic materials than with nonthematic materials, even without being cued with the theme. Experiments 5A and 5B showed that when instances contained conflicting features (i.e., features that are contradictory given background knowledge) participants were not more likely to construct FR categories with the thematic materials, unless they had a way of discounting such features.