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.