Sex differences on the HGSHS:A.

Over a 28-year period, 724 men and 1148 women completed the Harvard Group Scale of Hypnotic Susceptibility, Form A. Overall, women scored higher than men. This effect was most prominent on 6 of the 12 items, most (though not all) challenge items (identified by a principal-components analysis). The overall effect size was quite small. Results are discussed in terms of differences in item difficulty.

Hypnotic susceptibility as a predictor of participation in student activities.

In this study, Harvard Group Scale of Hypnotic Susceptibility: Form A scores for 458 college students were compared with college yearbook records of their participation in student activities. Students who scored low in susceptibility showed significantly less participation in activities than others who were either moderate or high in susceptibility. Overall, females showed higher levels of participation than males, but there was no significant interaction between gender and hypnotic susceptibility. Spectral analysis showed participation scores to be somewhat more strongly related to easier HGSHS:A items than to more difficult items in the manner predicted by two-factor theory. Closer examination of the results revealed that this effect was primarily due to the fact that low susceptible subjects participated significantly less in student activities than subjects who were either moderate or high in hypnotic susceptibility. The results suggest that future research should further examine the unique contribution of low susceptibility subjects to hypnosis theory and research.