Volume 36, Issue 5 (September 1991)
Effect of Posthypnotic Suggestions on the Accuracy of Preemployment Polygraph Testing
The efficacy of both a posthypnotic polygraph countermeasure suggestion and a posthypnotic ideomotor lie detection suggestion were examined within an analog preemployment screening context. Forty-five subjects were randomly assigned to one of three equalsized groups, controlling for their performance on the Harvard Group Scale of Hypnotic Susceptibility: Form A. Subjects assigned to one of the groups received the posthypnotic suggestion that the subject's index finger would rise whenever he or she lied during the polygraph test; subjects in another group were given a posthypnotic countermeasure designed to help them appear innocent whenever they lied; and those in the third group were not given either hypnotic intervention. None of the subjects given the ideomotor suggestion raised his or her finger when he or she lied during the polygraph test. The countermeasure suggestion also was ineffective, as was demonstrated by its failure to produce significantly more false negative responses.