An analysis of coordinated responding of pigeons.

Experimental analyses of coordinated responding (i.e., cooperation) have been derived from a procedure described by Skinner (1962) in which reinforcers were delivered to a pair of subjects (a dyad) if both responded within a short interval, thus satisfying a coordination contingency. Although it has been suggested that this contingency enhances rates of temporally coordinated responding, limitations of past experiments have raised questions concerning this conclusion. The present experiments addressed some of these limitations by holding the schedule of reinforcement (Experiment 1: fixed ratio 1; Experiment 2; variable interval 20 s) constant across phases and between dyad members and by varying, in different conditions, the number of response keys (one to three) across which coordination could occur. Greater percentages of coordinated responding occurred under the coordinated-reinforcement phases than under independent-reinforcement phases in most conditions. The one exception during the one-key condition of Experiment 1 appeared to be a consequence of variability introduced by the independent-reinforcement phase procedure. Furthermore, coordination percentages decreased with increasing response options under both schedules. These results confirm and extend the finding that coordination contingencies control higher rates of temporally coordinated responding than independent-reinforcement contingencies do.