Effectiveness of debriefing after a stress-producing deception

This experiment was carried out to determine if after deceiving Ss an E had sufficient credibility to effectively debrief the Ss. Ss in two stress groups were given false information indicating that when a signal light came on they would receive painful electric shocks. Ss in a no-stress group were not told about shocks. After being given the threatening instructions, Ss in one of the stress groups were debriefed concerning the deception (but the “shock electrodes” were not removed) while Ss in the other group were not debriefed. After this the signal light came on for all groups. Arousal was measured by pulse rates and self-reports. The results revealed that (a) the instructions about electric shocks increased the arousal levels of the two stress groups relative to the no-stress group, thus indicating that the deception was effective, and (b) after the signal light came on the stress group which had not been debriefed continued to show a high degree of arousal while the stress group which had been debriefed showed a reduction of arousal to the same low level of arousal as the no-stress group, thus indicating that the process of debriefing had been effective.