The effects of response cost and response restriction on a multiple-response repertoire with humans

In two experiments a multiple-response repertoire of four free-operant responses was developed with university students as subjects using monetary gain as reinforcement. Following baseline, one of the responses was reduced either by making monetary loss contingent upon it (response cost) or by removing it from the repertoire (response restriction). In Experiment 1 a multielement baseline design was employed in which baseline and restriction or response-cost contingencies alternated semirandomly every 3 minutes. In Experiment 2 a reversal design was employed (i.e., baseline, restriction or response cost, then baseline), and each response required a different amount of effort. Both experiments had the following results: (a) The target response decreased substantially; (b) most nontarget responses increased, and the rest remained near their baseline levels; and (c) no support was found for Dunham's hierarchical, most frequent follower, or greatest temporal similarity rules. For several subjects, the least probable responses during baseline increased most, and the most probable responses increased least. Furthermore, in Experiment 2, responses with the lowest frequency of reinforcement increased most (for all 7 subjects), and those with the greatest frequency of reinforcement increased least (for 5 subjects).