Schizophrenics with high or low levels of frontalis muscle tensions while at rest (base‐line) were instructed to respond (button‐press) at different rates, allowed to respond at any rate they preferred, and reinforced for responding under different schedules of reinforcement. Information about response–reinforcement relationships was provided for each reinforcement schedule. High and low levels of base‐line muscle tensions were associated with high and low rates of preferred and reinforced responding, respectively. Response rates also varied with different contingencies of reinforcement. Further, the data permit the following tentative conclusions: (a) under certain contingencies, responding may vary more with base‐line muscle tensions than with the contingency of reinforcement, and (b) instructed rates of responding may not be correlated consistently with base‐line musc