Direct and indirect hypnotic induction techniques and individual characteristics

Abstract

The purposes of the present study were to compare the efficacy of direct and indirect hypnotic induction techniques and to examine the relationship between these methods and three individual variables: defensiveness, locus of control and authoritarianism. A group of 117 male and female students at a Southwestern university were used as subjects. Subjects were randomly assigned to two treatment groups: (1) direct hypnotic induction, and (2) indirect hypnotic induction. Treatment consisted of the administration of a tape recorded version of either the direct or indirect hypnotic induction. The study manipulated only induction; form of suggestion remained constant. Success was defined as the total number of responses to 10 possible hypnotic suggestions, using a modified self-report form of the Harvard Group Scale of Hypnotic Susceptibility, Form A. The subject variables of defensiveness, locus of control, and authoritarianism were measured using the Defensiveness Scale of the Psychological Screening Inventory, the Rotter Internal-External Locus of Control Scale, and the California F Scale, respectively. A two sample t-test was used to compare means of response scores to hypnosis between direct and indirect hypnotic induction groups. Pearson product-moment and multiple correlation coefficients were used to investigate the relationship between type of hypnotic induction and individual characteristics. Results showed non-significant differences between direct and indirect induction groups on hypnotic response. Thus the subject who received an indirect hypnotic induction responded to hypnotic suggestions at a similar level to the subject who received a direct hypnotic induction. Results also indicated no relationship between response to direct or indirect hypnotic induction, and defensiveness, locus of control, and authoritarianism. This study implied the robustness of hypnotizability, regardless of method of induction or personality characteristics, and the equivalence of direct and indirect methods in producing response to hypnotic suggestion in the general, non-clinical population.