Instructional set and the relative efficacy of hypnotic and waking analgesia.

Abstract
The hypothesis that hypnotic analgesia is intrinsicially more effective than waking analgesia was tested by administering both treatments to the same subjects while varying expectations concerning treatment efficacy. Subjects given equivocal information about the relative efficacy of the two treatments exhibited larger pain tolerance increments in hypnotic than in waking analgesia. However, subjects explicitly informed that waking analgesia was the more effective exhibited equivalent pain tolerance increments in the two treatments. Although these subjects rated themselves as deeply hypnotized on their hypnotic analgesia trial, they rated themselves as much less hypnotized on their waking analgesia trial. These findings contradict both the idea that hypnotic analgesia is more effective than waking analgesia and the idea that subjects in waking analgesia conditions reduce pain by inadvertently drifting into hypnosis.