The effects of polygraphic feedback on the breaching of verbal reports

The present study investigated the malleability of verbal reports by manipulating pressures to comply following hypnotic procedures. On each of three trials, high and medium hypnotizable subjects (N=45) rated the loudness of a tone ten seconds following it's termination. Trial 1 was a baseline while Trial 2 was preceded by a hypnotic deafness suggestion. Following the third trial (following the experience of the tone but before the report) subjects received either (1) no verbal instruction, or (2) a compliance instruction which cued the subjects about appropriate responding. Following their loudness ratings, half of the compliance subjects but all of the control subjects received polygraphic feedback that they were not being honest. All subjects were required to give a second loudness rating. Higher loudness ratings here compared to the earlier report indicated that subjects had reported significant hearing reduction to the Trial 2 suggestion for deafness and to the compliance instruction. The polygraphic feedback removed the demand to comply and verified that the Trial 3 reports had been biased. The results confirm that compliance is an active ingredient in hypnotic responding.