Involuntary experiencing and the performance of hypnotic test suggestions.

This experimental study examined 2 questions: (a) Does the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) tap the "classic suggestion effect" and (b) does the wording of postexperimental questions bias subjective reports of hypnotic subjects? Results indicated that a significant minority of individuals who "passed" test suggestions by objective behavioral criteria reported performance as occurring voluntarily, and participants who "failed" test suggestions reported performance of behaviors as occurring involuntarily. Participants' reports of the involuntariness of their experience during performance of hypnotic test suggestions were not significantly influenced by the wording of questions. Implications of these findings for experimental research and clinical practice are discussed.