Human response rates and causality judgments on schedules of reinforcement

Experiments examined the effect of various relationships between a response (an investment made in the context of a game) and an outcome (a return on the investment) on judgments of the causal effectiveness of the response. I n Experiment 1, the time between successive outcomes obtained on a variable ratio (VR) schedule became the successive interval criterion for a yoked v ariable interval (VI) schedule. Response rates were higher on the VR than t he VI schedule. In Experiment 2, the number of responses required per outco me on a VR schedule was matched to that on a master VI 20-s schedule. The r atings of causal effectiveness of the response, and the response rate, were higher in the VR schedule. In Experiment 3, a VI schedule with a reinforce ment requirement for a short IRT produced higher response rates and higher causality judgments than a simple VI schedule. These results are taken to c orroborate the view that schedules are a determinant of both response rates and causal judgments in humans. (C) 2001 Academic Press.