Behavioral persistence in carrying out a posthypnotic suggestion beyond the hypnotic context: a consideration of the role of perceived demand characteristics.

Compliance with a posthypnotic suggestion (PHS) to carry out a specific behavior in a subsequent nonhypnotic setting was investigated in high and medium hypnotizable participants. The target behavior--solicited by either a PHS given during hypnosis, a waking social request, or both--was to be performed daily for an unspecified period of time. Findings indicated that the waking request alone yielded a high level of compliance, particularly among medium hypnotizable participants. In contrast, highly hypnotizable participants who received the PHS coupled with instructions for posthypnotic amnesia exhibited considerable variation in responding, whereas high hypnotizables, who received either a waking request, or a combination of PHS and waking request, performed similarly to medium hypnotizables. Postexperimental interview data suggest that perceived demand characteristics may contribute to variation in the persistence of posthypnotic behavior outside the hypnotic context.