Operational thought and the acquisition of taxonomic relations involving figurative dissimilarity.

Abstract

Atypical exemplars of taxonomic categories (e.g., clothing, furniture) differ from more typical exemplars along figurative dimensions of perceptual and contextual similarity. The advent of operational thought might be expected to facilitate category acquisition because it engenders a competence to suppress figurative dissimilarities and focus on nonfigurative similarities (e.g., common function). Age- and grade-equivalent preoperational and concrete operational groups were given oddity, sort, and category membership tasks with pictorial stimuli. Concrete operational subjects showed a greater appreciation than preoperational subjects for taxonomic relations involving atypical exemplars. Subjects of both cognitive levels could appreciate taxonomic relations involving strictly typical or moderately typical exemplars of a category. Results are interpreted as supporting a contention that meanings become more general with the emergence of operational thought. Superordinate concepts are abstract organizations such as clothing, furniture, fruit, and animal, having basic object concepts (e.g., skirt, pants; chair, table; apple, banana; bird, fish) as exemplars. The basic object level of a conceptual hierarchy is the most inclusive level at which the exemplars of a concept share a large number of features (Rosch, Mervis, Gray, Johnson,