Individual differences in fluid intelligence moderate the interleaving effect for perceptual category learning

The interleaving effect refers to the finding that repeatedly switching between categories during study or practice enhances learning relative to focusing on only one category at a time. Two studies investigated whether this effect is moderated by individual differences in fluid intelligence (gF), episodic memory (EM) ability, and/or working memory capacity (WMC). In Study 1 (undergraduate students) and Study 2 (adult online participants), higher gF scores were associated with larger interleaving effects for perceptual categories (artists' painting styles). Additionally, higher EM ability was associated with larger interleaving effects for perceptual categories in Study 1, whereas an analogous pattern was observed for WMC in Study 2. There were no indications that the investigated cognitive abilities moderated the interleaving effect for text-based categories (psychological disorders). Overall, these findings suggest that higher-ability learners benefit especially from interleaving in the case of perceptual category learning, with attendant theoretical and pedagogical implications.