An investigation of the factor structure of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A)

Abstract In order to investigate the effects of the hypnotic state a standardized hypnosis session was conducted with 144 subjects in a controlled laboratory study. The induction of a hypnotic trance in the German version of the Harvard Group Scale of Hypnotic Susceptibility (HGSHS:A by Shor and Orne, 1962) was tape‐recorded and used as the treatment. The HGSHS:A seems to be a reliable measure of suggestibility and hypnotizability. This is underlined by the consistent results of a factor analysis on the depths of hypnosis that is in agreement with former studies. Descriptive data analyses with a sufficient number of subjects of high and low suggestibility suggest that our hypnosis induction by tape is an effective method of producing a hypnotic trance. Analyses of within‐subjects variables did not reveal any valid predictors of hypnotizability, thereby confirming the need of screening instruments such as the HGSHS. Copyright © 2006 British Society of Experimental & Clinical Hypnosis. Published by John Wiley & Sons, Ltd.