Diurnal variations in hypnotic responsiveness: is there an optimal time to be hypnotized?

With a sample of nearly 700 undergraduate students, the authors found support for diurnal variations in hypnotic responsiveness. Administering the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) in the morning or evening resulted in higher average scores than from afternoon sessions. The authors replicated this finding using a second independent sample. In the primary study, participants indicated the time of day that they are most alert. Matching self-reported preferred time of the day with HGSHS:A administration time did not improve hypnotic responsiveness. Considering this as well as past research, the authors argue that mid-morning may be the optimal time to be hypnotized and afternoon the least favorable.