Correlated properties in natural categories

In most models of categorization, the properties of category members are assumed to be independent of one another. Several sources of evidence suggest, however, that this assumption may be false, and furthermore, that the nonindependence of properties may have important consequences for categorization. In the experiments presented here, it was demonstrated that properties of natural categories occur in systematic relation to one another rather than independently. Property relations did not seem to influence typicality judgments when the potential impact was assessed using models similar to those in the concept-learning literature. In a further experiment, under different conditions, property relations did influence typicality, suggesting that knowledge of such relationships may mainly concern certain particularly salient or functional combinations.