A new paper by Categorization Lab members Rachel Rabi, Sarah Miles, and Paul Minda that was just published in the Journal of Experimental Child Psychology explored category learning by young children and adults. You can read the paper here. We conducted two experiments. The participants in our experiments were were asked to learn a set of categories for which both a single-feature rule and/or overall similarity would allow for perfect performance. Other rules allowed for suboptimal performance. After the participants learned the categories, we presented them with transfer stimuli (Experiments 1 and 2) and single features (Experiment 2) to help determine how the categories were learned. In both experiments, we found that adults made significantly more optimal rule-based responses to the test stimuli than children. Children showed a variety of categorization styles, with a few relying on the optimal rules, many relying on suboptimal single-feature rules, and only a few relying on overall family resemblance. We interpreted these results within a multiple-systems framework (like CoVIS). Children may show the patterns that they do because they lack the necessary cognitive resources to fully engage in hypothesis testing, rule selection, and verbally mediated category learning.