The surreptitious observation design: an experimental paradigm for distinguishing artifact from essence in hypnosis.

Administered a hypnotic induction and 5 standard hypnotic suggestions twice via audiotape to a group of high-hypnotizable subjects and a group of low-hypnotizable simulators. During the first administration, subjects were led to believe that they were alone. However, their behavior was surreptitiously recorded on videotape and observed on a video monitor. The second administration occurred in the presence of an experimenter who had not been informed of group assignment. When unaware that they were being observed, simulators were significantly less responsive to suggestions than they were when openly observed. In contrast, the behavior of nonsimulating subjects was not affected by the presence of an experimenter. These data indicate that the responses of highly hypnotizable subjects to standard hypnotic suggestions cannot be accounted for in terms of simple compliance with experimental demand.