Exploratory Study of Equivalence under Conjoint Select and Reject Control

Carrigan and Sidman Journal of the Experimental Analysis of Behavior, 58, 183-204, (1992) proposed that select and reject arbitrary conditional relations are equivalence relations, each resulting in the emergence of alternative stimulus equivalence classes. The standard matching to sample (MTS) procedure can potentially teach both select and reject conditional relations, which apparently would prevent the emergence of equivalence relations, although there is extensive evidence for the emergence of equivalence with the standard MTS procedure. One possibility is that participants trained with the standard MTS procedure predominantly learn one type of control over the other. Experiment 1 explores the implementation of a Detached-MTS procedure, which separately trains the select and reject conditional relations involved in the Standard-MTS procedure. The results suggest that the emergence of equivalence relations may be compatible with conjoint select and reject conditional control. In Experiment 2, the Detached-MTS procedure succeeds in replicating the emergence of equivalence under exclusive select control but not under exclusive reject control, which conditions the findings of Experiment 1. The sources of control associated with the emergence of equivalence in the standard MTS procedure and some methodological issues of the Detached-MTS procedure are discussed.