Induction with cross-classified categories

One of the main functions of categories is to allow inferences about new ob jects. However, most objects are cross-classified, and it is not known whet her and how people combine information from these different categories in m aking inferences. In six experiments, food categories, which are strongly c ross-classified (e.g., a bagel is both a bread and a breakfast food), were studied. For each food, the subjects were told fictitious facts (e.g., 75% of breads are subject to spoilage from Aspergillus molds) about two of the categories to which it belonged and then were asked to make an inference ab out the food (e.g., how likely is a bagel to be subject to spoilage from As pergillus molds?). We found no more use of multiple categories in these cas es of cross-classification than in ambiguous classification, in which it is uncertain to which category an item belongs. However, some procedural mani pulations did markedly increase the use of both categories in inferences, p rimarily those that focused the subjects' attention on the critical feature in both categories.