Causality and the Categorization of Objects and Events

Two series of experiments investigating the nature of category structure are presented. The studies focused on object categories and event categories. It was found that, for both objects and events, property centrality (a rating of how important the property is to the category) is not entirely predicted by property typicality (how frequently the object or event possesses that property). By contrasting conditions in which adult subjects rank-ordered properties according to various criteria, it was found that causal theories about the role of the properties in the categories strongly predicted property centrality, although recognitional and definitional factors did play some role. This relationship held for both familiar and newly acquired categories. Recent empirical work on the attribution of causal relationships to sequences of events is reviewed. The evidence from both the past work and the current studies indicates humans do indeed have causal theories which they use to categorize objects and events