Humans’ Choice between Different Reinforcer Amounts and Delays: Effects of Choice Procedures and Monetary Deduction

Abstract

Human subjects were exposed to concurrent-chains schedules in which reinforcer amounts or delays were varied in the terminal links and consummatory responses were required to receive points later exchangeable for money. Two independent variable-interval 30-s schedules or a single variable-interval 15-s schedule were in effect during the initial links and delay periods were defined by fixed-time schedules used in the terminal links. In addition to varying reinforcer amount and delay, two different choice procedures were studied for two different groups and a monetary deduction procedure was studied, within subjects, under independent scheduling procedure. The human subjects preferred the larger of two different reinforcer amounts and the shorter of two different reinforcer delays. The degree of preference was higher in the independent scheduling procedure than in the nonindependent scheduling procedure and there was no substantial difference in preference between the absence and presence of the monetary deduction procedure.