title: Stimulus equivalence: testing Sidman's (2000) theory.
abstract: Sidman's (2000) theory regarding the origin of equivalence relations predicts that a reinforcing stimulus common to distinct equivalence classes must drop out of the equivalence relations. This prediction was tested in the present study by arranging class-specific reinforcers, R1 and R2, following correct responding on the prerequisite conditional discriminations (Ax-Bx, Cx-Bx) for two stimulus classes, A1B1C1 and A2B2C2. A class-common reinforcer, R3, was presented following correct responding on the prerequisite conditional discriminations for a further two stimulus classes, A3B3C3 and A4B4C4. Sidman's theory predicts reinforcer inclusion within Classes 1 and 2 only, given this training arrangement. Experiment 1 tested for the emergence of four equivalence classes and of stimulus-reinforcer and reinforcer-stimulus relations in each class. Four of the 6 subjects demonstrated the reinforcer-based relations in all four equivalence classes, rather than in only those classes with a class-specific reinforcer, as Sidman's theory predicts. One of the remaining 2 subjects showed the reinforcer-based relations in three of the four classes. Experiment 2 extended these findings to document the emergence of interclass matching relations based on the common reinforcer R3, in 5 of 6 subjects, such that a Class 3 sample occasioned the selection of a Class 4 sample when the Class 3 comparison was absent, and similarly, a Class 4 sample occasioned the selection of a Class 3 comparison when the Class 4 comparison was absent. These interclass relations emerged despite the simultaneous maintenance of Class 3 and 4 baseline conditional discriminations, so that the Class 3 and 4 stimuli and reinforcer simultaneously were, and were not, part of a single larger equivalence class. These data are irreconcilable with Sidman's theory, and question the utility of the application of the equivalence relation in describing derived stimulus relations.
authors.affiliation: Department of Psychology, University of Auckland, New Zealand. saraminster@gmail.com
authors.forename: Sara Tepaeru
authors.initials: ST
authors.lastname: Minster
authors.forename: Max
authors.initials: M
authors.lastname: Jones
authors.forename: Douglas
authors.initials: D
authors.lastname: Elliffe
authors.forename: Suresh D
authors.initials: SD
authors.lastname: Muthukumaraswamy
mesh_terms: D000328:Adult; D004193:Discrimination Learning; D005246:Feedback; D005260:Female; D006801:Humans; D008297:Male; D011582:Psychological Theory; D012054:Reinforcement, Psychology; D014796:Visual Perception