Early development of perceptual expertise: within-basic-level categorization experience facilitates the formation of subordinate-level category representations in 6- to 7-month-old infants.

A behavioral manifestation of perceptual expertise is the shift in recognition downward toward the subordinate level. Here, a familiarization-novelty preference procedure was used to determine whether 6- to 7-month-old infants could be induced to form category representations for cats and dogs at the subordinate level. In Experiment 1, the infants succeeded in forming subordinate-level category representations for beagle dogs and Siamese cats, but only when provided with previous experience on a subordinate-level category-formation task from within the same basic-level category (i.e., Saint Bernard dogs or tabby cats). When the prior category-formation task involved a different basic-level category, subsequent subordinate-level category learning was not in evidence. The preferences in Experiment 1 were shown in Experiments 2 and 3 not to be attributable to a priori preference or within-category discrimination failure. The findings suggest that within-basic-level categorization experience can facilitate the formation of subordinate-level category representations in the first half-year of life.