Minster, S. T., Jones, M., Elliffe, D. & Muthukumaraswamy, S. D. (2006).
Stimulus equivalence: Testing Sidman’s (2000) theory.
Journal of the Experimental Analysis of Behavior, 85, 371-391.
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.
stimulus control, equivalence relations, outcome-specific consequences, matching to sample, mouse-click, humans