The relationship between expectation and hypnotic susceptibility: a literature review

Researchers do not completely understand how hypnosis functions or what variables can predict an individual to have a high or low hypnotic susceptibility. Expectation is a variable that has been studied, but researchers disagree on the effect it has on hypnotic susceptibility. The purpose of this paper is to obtain a comprehensive understanding of how personal expectations affect hypnotic susceptibility. To this end, a critical literature review was conducted on studies dating from 1964 to 2017 examining the relationship between expectation and hypnotic susceptibility of college students. To be included in this review, all studies were required to measure both the participants' expectations of being hypnotized and their hypnotizability with a hypnotic susceptibility scale. An exhaustive search of the PsycINFO database identified 19 studies satisfying the listed and other requirements. Results indicated that expectancies of being hypnotized and hypnotic susceptibility have a very small correlation. Expectations assessed after the induction procedure tended to obtain higher correlations with hypnotic susceptibility than expectations assessed before the induction. Additionally, studies that assessed expectation by providing participants with a detailed written description of each suggestion tended to obtain higher correlations with hypnotic susceptibility than studies that did not give participants any information about the suggestions. When all is considered, expectation does not appear to be highly correlated with hypnotic susceptibility; however the modest correlation observed remains worthy of study as it is higher than other tested variables.