Palmer, D. C. (2002). Psychological essentialism: A review of E. Margolis and S. Laurence (eds.),Concepts: Core Readings. Journal of the Experimental Analysis of Behavior, 78, 597-607.

Concepts: Core Readings (1999) is an edited volume of articles representing five major theories of concepts within cognitive psychology. Of the five, only the prototype theory can be interpreted in terms arising from a behavioral analysis. Two conceptual problems pervade nearly all of the papers in the volume. The first is an implicit commitment to essentialism; concepts are reified and are commonly discussed as though they have essential properties. Second, the theories suffer from a defective theory of verbal behavior. No distinction is made between verbal operants and words drawn from a hat.

Key words: concepts, essentialism, prototype theory, stimulus classes, units of analysis, verbal behavior