RESPONSE TRANSFER BETWEEN STIMULI IN GENERALIZED EQUIVALENCE CLASSES - A MODEL FOR THE ESTABLISHMENT OF NATURAL KIND AND FUZZY SUPERORDINATE CATEGORIES

Two equivalence classes were formed by college students through traini ng of AB, BC, and CD relations. The A, B, and C stimuli in both classe s were nonsense words. The D stimulus in Class 1 was a short line; the D stimulus in Class 2 was a long line. Post-class-formation generaliz ation tests of emergent relations were conducted to determine which in termediate length lines (variants of the D stimuli) also acted as clas s members. Those variants and the A, B, C, and D stimuli formed a gene ralized equivalence class. After different responses were trained to t he A1 and A2 stimuli, the response trained to the A1 stimulus transfer red to the other Class-1 stimuli and the response trained to the A2 st imulus transferred to the other Class-2 stimuli. Responding also trans ferred to the variants that acted as members of each generalized equiv alence class, indicating that the stimuli in each generalized equivale nce class also acted as members of a corresponding functional class. F or the line variants that were members of a generalized equivalence cl ass, response transfer from the A stimuli was very highly predicted fr om the generalization gradients of the emergent relations. The process es that account for the formation of a generalized equivalence class a nd the transfer of responding between members of such a class will be used to account for the development of natural kind and superordinate fuzzy categories.