The role of explanation in categorization decisions

Research into the role of explanation on the categorization process has yielded conflicting conclusions. Some theorists stress the importance of explanation, arguing that explanations provide a causal structure necessary to the categorization process. Others discount its significance, arguing that explanation is neither necessary nor sufficient for categorization. Experimentally, explanation has shown modest success in accounting for some categories but not others. Across three experiments, we test whether the central features of a category are the ones that capture the most explanatory structure. The objectives of the current study are threefold: to determine the importance of explanation in natural kind and artifact categorization; to understand the implications of feature correlations as they relate to explanation; and to further delineate the benefit of explanation outside of a functional role. Experiment 1 demonstrates that explanation plays a more dominant role in artifact versus natural kind categorization. Experiment 2 provides evidence that correlated features are neither necessary nor sufficient for categorization. Moreover, it demonstrates that, in the absence of correlation, people still rely on explanation for artifacts but not for natural kinds. Experiment 3 tests to what extent functional information underlies explanation in artifact categorization. We demonstrate that functional relations are not necessary for explanatory‐based categorization. Our results, coupled with previous evidence, suggest a dichotomous role for explanation‐based categorization. On the one hand, explanation is virtually ignored when categorizing biological kinds; on the other, explanation fosters artifact categorization. Implications for categorization and category‐specific disorder are considered.