An investigation into the relationship between hypnotic suggestibility and tendency to engage in ideomotor action

Abstract

The relationship between hypnotic suggestibility and tendency to engage in ideomotor action was measured in 71 psychology undergraduates at Plymouth University. Each participant’s level of hypnotic suggestibility was measured with a series of suggestibility tests, and their tendency to engage in ideomotor action was measured with two computer-based tasks - an action planning task and an imitation task. It was found that participants were faster at ideomotor-compatible tasks, such as backward action-planning trials (t(59) = -3.1, p = .003) and congruent imitation trials (t(57) = -14.46, p < .001). It was also found that participants made more errors in non-ideomotor-compatible tasks, such as forward action-planning trials (t(59) = -3.28, p = .002) and incongruent imitation trials (t(57) = -6.75, p < .001). This suggests that people find it easier to engage in ideomotor action, as they responded faster and more accurately in ideomotor-compatible tasks. Furthermore, a pairwise correlation found a relationship between suggestibility and error rates in the imitation task (r = +.36, n = 56, p = .007, two-tailed). Increased error rates in the imitation task could be a result of having fewer inhibitory thoughts. This would prevent the participant from overriding their automatic, ideomotor responses, leaving them vulnerable to suggestion, as they cannot override these either. This indicates that some people are more suggestible than others as they have fewer inhibitory thoughts. Implications for the development of tailored medicine and hypnotherapy are discussed.