Do the Stanford scales tap the “classic suggestion effect”?

Abstract

Weitzenhoffer has recently challenged the adequacy of the Stanford Hypnotic Susceptibility Scales, Forms A and C (SHSS:A, SHSS:C) of Weitzenhoffer and Hilgard (1959, 1962) on the grounds that they do not tap the “classic suggestion effect.” The effect in question concerns the experience of nonvolition that has historically defined hypnotic responsiveness. The present investigation addressed Weitzenhoffer's concerns by assessing the experience of nonvolition associated with each item of SHSS:A, and analyzing the data in 2 different ways. The first analysis demonstrated that there were frequent mismatches of behavior and experience at the level of items, such that passed items were volitionally performed about 20% of the time, which was approximately the same relative frequency that failed items were experienced as non-volitional. The second analysis focused on Ss' total scores across all the items of SHSS:A and SHSS:C. SHSS:A and SHSS:C scores were then correlated with each other and with composite indices of nonvolition based on all the SHSS:A items. This analysis revealed that there was, for the most part, a much higher relationship between the scale scores and the experience composites than obtained between behavior and experience at the level of items. The results of the present investigation suggest that the entire SHSS:C taps the classic suggestion effect about twice as well as individual SHSS:A items do.