Sleepiness may predict hypnotizability, while personality traits do not.

Sleepiness and personality traits have been controversially reported as associated to individual hypnotizability level i.e. receptiveness to hypnotic suggestions and behave accordingly. In this study, we further investigate the relationship between the level of general daytime sleepiness and personality traits with the level of hypnotizability. Seventy-eight healthy young volunteers (34 women) completed the fast assessment of general daytime sleepiness and personality with the Epworth Sleepiness Scale and the 10-item Big Five Inventory respectively, and underwent hypnotic evaluation through the Harvard Group Scale of Hypnotic Susceptibility Form A (HGSHS:A). Main findings revealed a correlation between sleepiness and hypnotizability levels, and no influence of personality traits. Interestingly, women exhibited higher levels of hypnotizability compared to men. Taken together, these results suggest that sleepiness assessment might be considered as a predictive tool to hypnotic suggestions, which would offer practical insight for enhancing hypnosis intervention efficacy.