Multiple hypnotizabilities: differentiating the building blocks of hypnotic response

Although hypnotizability can be conceptualized as involving component subskills, standard measures do not differentiate them from a more general unitary trait, partly because the measures include limited sets of dichotomous items. To overcome this, the authors applied full-information factor analysis, a sophisticated analytic approach for dichotomous items, to a large data set from 2 hypnotizability scales. This analysis yielded 4 subscales (Direct Motor, Motor Challenge, Perceptual-Cognitive, Posthypnotic Amnesia) that point to the building blocks of hypnotic response. The authors then used the subscales as simultaneous predictors of hypnotic responses in 4 experiments to distinguish the contribution of each component from general hypnotizability. This analysis raises interesting questions about how best to conceptualize and advance measurement of the ability to experience hypnosis.

Department of Psychology, University of Waterloo, Waterloo, Ontario, Canada. ewoody@uwaterloo.ca