Comparisons promote a tradeoff between generalization and individuation

Qualitative comparison provides learning opportunities that support a range of cognitive abilities. The present research clarifies how the contrasting goals of qualitative comparison, processing similarities versus differences, contribute to the overall impact that comparison has on learning. We argue that attending to similarities produces memory traces that are dissociable from those left by attending to differences, and that these memory traces reflect a tradeoff between generalization and individuation. Across two preregistered experiments, participants either attended to similarities or differences between stimuli. We show that whereas attending to similarities yielded better performance on a category recognition task (Experiment 1), attending to differences yielded better performance on an old/new recognition task (Experiment 2). Comparison thus serves as a learning opportunity that enables agents to manage the generalization-individuation tradeoff by shifting their attention toward similarities or differences.