Demand characteristics and the response suppression hypothesis

Abstract

College student subjects were given the opportunity to pull a plunger (Linsley manipulandum) or press a small panel in a three-stage design. Five minutes of free access (baseline) was followed by a 5-min contingency phase in which 10 responses to the plunger were required to free the panel for a single press. This was followed by a 5-min return to baseline. From a postexperiment questionnaire, subjects were judged to have been either aware or unaware of the contingent relation between the plunger and the panel. Those judged to have been aware yielded much higher rates of plunger pulling during the contingent phase and were more active during baseline measurement. These results raise problems for the response suppression methodology of Eisenberger, Karpman, and Trattner (1967), since they can be as readily accounted for by Orne’s (1962) demand hypothesis.