Does a General “G Factor” Best Account for Hypnotizability?

ABSTRACT

The lead article in this issue of the International Journal of Clinical and Experimental Hypnosis (IJCEH), entitled, “Confirmatory Factor Analysis of the Elkins Hypnotizability Scale in a Clinical Population”, reports on a factor analysis of hypnotizability scores in a clinical population of postmenopausal women. The results found evidence for a general hypnotizability latent variable. This finding suggests a general “G factor” may best account for hypnotizability. More research is needed, however, if confirmed in future research would lead to a new understanding of hypnotizability as having a single-factor structure. Existing research proposes greater recognition of the natural capacity of humans to intentionally alter their own experiences. Another study reports that perceptions of clinical hypnosis are positive among the public and healthcare providers, but more education of healthcare providers about hypnotherapy is needed. Additional articles are presented that examine the feasibility and potential benefit of clinical hypnosis in treatment of pain and distress among patients with fibromyalgia syndrome and in improving sleep disturbances in individuals with mild cognitive impairment.

Introduction

Hypnotizability is defined as, “an individual’s ability to experience suggested alterations in physiology, sensations, emotions, thoughts, or behavior during hypnosis” (Elkins et al., 2015, p. 382). Prior research has persuasively established that individual differences in hypnotizability exist (Bates, 1993; Hilgard, 1965). Furthermore, multiple studies have shown a generally normal distribution of hypnotizability scores with most individuals scoring in a moderate range (Hilgard, 1965; Kekecs et al., 2016; Woody et al., 2005) and a small proportion scoring in the low or very high range. Several past studies have suggested that hypnotizability may be a multifactorial construct. However, it is unknown as to whether hypnotizability is best accounted for as being multifactorial or as a general factor with subcomponents. The lead article, entitled “Confirmatory Factor Analysis of the Elkins Hypnotizability Scale in a Clinical Population” (Zimmerman et al., 2024), addresses this issue. The Elkins Hypnotizability Scale (EHS) (Elkins, 2022; Kekecs et al., 2021) was administered to 173 women, with a mean age of 54.61 years. The results found the EHS reflected a unidimensional structure in which the individual items on the scales are direct indicators for a general hypnotizability latent variable. The results of this study are important and, if confirmed in future research, may led to new understanding and conceptualization of hypnotizability having a single-factor structure.

Related to advancing our understanding of hypnosis and hypnotizability, a thought-provoking article by Dell (2024) raises the question, “What is the Source of Hypnotic Responses?” The author proposes greater recognition of the natural capacity of humans to intentionally alter their own experiences. Cultural and historical factors that may have contributed to conflation of this natural ability with hypnosis, suggestibility, and hypnotizability are explored and discussed.

Attitudes toward clinical hypnosis among the general population and patients receiving health care is examined in a scoping review (Szmaglinska et al., 2024). The results found that attitudes toward hypnotherapy were consistently positive. This is especially true when hypnotherapy is provided by licensed professionals. However, awareness of hypnotherapy was found to be low in the healthcare sector. More education and dissemination of hypnotherapy research among health care providers is needed to increase awareness, accurate information, and benefits. For example, the authors found that research on attitudes toward clinical hypnosis in cancer care is rather minimal, and further initiatives to educate health care providers is needed.

An example of the type of well-conducted research that can inform health care providers and the public about the benefits of hypnotherapy is provided in this issue of the International Journal of Clinical and Experimental Hypnosis. Ozgunay et al. (2024) report on a prospective randomized clinical trial of the adjuvant effect of hypnotherapy in treatment of female patients with fibromyalgia syndrome (FMS). The results demonstrate that a brief standardized hypnosis intervention that includes teaching patients’ self-hypnosis, significantly reduced pain, depression, and anxiety symptoms in this clinical population. Further, the quality of life significantly improved in patients with FMS in comparison to no treatment control.

Additional evidence for the potential benefits of hypnotherapy in clinical populations is provided by Elkins et al. (2024) in a feasibility of study of a hypnosis intervention for sleep disturbances in individuals with mild cognitive impairment (MCI). The incidence of poor sleep quality is very high among individuals with MCI. Poor sleep increases risk of stress, memory impairments, and progression of dementia among individuals with MCI. Sedating medications are generally avoided due to the impact on attention and memory in MCI. The present study by Elkins et al. (2024) aimed to determine the acceptability, adherence to self-hypnosis, and feasibility of objective and subjective measures of sleep duration, quality, and daytime sleepiness as well as the feasibility of randomization to an active hypnosis intervention or sham hypnosis control. Results showed a high degree of adherence and acceptability of the hypnosis intervention and for randomization. While the study was not powered to determine efficacy, significant improvements in sleep quality, duration, and daytime sleepiness was found for the hypnosis intervention vs sham hypnosis control. These findings are encouraging and provide the pilot data needed for further study in a fully powered randomized clinical trial. If proven to be effective, hypnotherapy could be a viable alternative for improving sleep in individuals with MCI.

Taken together, these articles provide new insights into the factor structure of hypnotizability and perceptions of hypnosis and hypnotherapy among the public and health care providers. Furthermore, the potential benefits of clinical hypnosis among patients with FMS is reported. Also, the feasibility of a hypnosis intervention for improving sleep duration and quality among individuals with MCI is established. These findings have implications for clinical practice, new conceptualizations of hypnotizability, and directions for future clinical research.