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Theories of Hypnosis in General   Psychological Explanations of Specific Phenomena 

Professional Societies                Professional Journals      Recommended Reading            Glossary  


The dual nature of hypnosis -- in which alterations in consciousness occur in an interpersonal context -- has meant that theoretical attempts to understand the phenomenon have been entangled in dichotomies. This has been the case since Mesmer, who thought his effects were due to a magnetic fluid, while the French royal commission attributed them to imagination. Charcot thought hypnotizability was a matter of neurology, while Liebeault and Bernheim emphasized the importance of suggestion. Sometimes these dichotomies are manifested within a single individual: Braid began with ideas about the paralysis of nerve centers, and ended up emphasizing attention, imagination, expectation, and personality. Click on the picture above and to the right to see an enlarged version of Charcot hypnotizes a patient in his clinic, from Henri Ellenberger's The Discovery of the Unconscious (1970).

Theories of Hypnosis in General

In the modern era these dichotomies are still visible, if somewhat obscured by theoretical nuance. Thus, the traditional view that hypnosis involves a "special" or "altered" state of consciousness is opposed by a variety of social-psychological or cognitive-behavioral views which assert that hypnotic behavior is a result of processes that are in every sense ordinary. However, there is considerable heterogeneity of viewpoint within each camp, which is sometimes ignored by the other side. Among those sometimes labeled state theorists are cognitive psychologists who think that hypnosis involves dissociative processes, psychoanalysts who invoke adaptive regression in the service of the ego, and neuroscientists who emphasize the inhibition of cortical structures. Among the critics of the state view are those who claim that hypnotic effects can be produced in the absence of a hypnotic induction, so long as individuals are appropriately motivated and instructed. Other theorists tend to emphasize the importance of prescriptive social roles played out by both hypnotist and subject. Still others focus on the self-fulfilling effects of expectancies. Finally, some theorists focus on the role of attributional processes and self-deception. While some social-psychological and cognitive-behavioral theorists have spent a great deal of time debunking exaggerated or erroneous claims about hypnosis, this has been no less true for some state theorists.

Although it is sometimes popular to portray this theoretical dispute as a kind of enduring debate, there is as much controversy within each camp as there is between camps. And, in the final analysis, most hypnosis research is designed more to illuminate the nature of specific hypnotic phenomena such as analgesia or amnesia than to provide evidence for any overarching theory of hypnosis.

Psychological Explanations of Specific Phenomena  

A great deal of controversy surrounds the explanation of hypnotic analgesia. On the one hand, it is argued that hypnotized individuals employ such techniques as self-distraction, stress-inoculation, cognitive reinterpretation, and tension-management. While there is no doubt that cognitive strategies can reduce pain, their success, unlike the success of hypnotic suggestions, is not correlated with hypnotizability, and thus is unlikely to be responsible for the effects observed in hypnotizable individuals. Rather, hypnotic analgesia seems to be associated with a division of consciousness that prevents the perception of pain from being represented in conscious awareness, without altering the physiological effects of the pain stimulus.

A great deal of research has also been devoted to the posthypnotic amnesia frequently displayed by hypnotizable individuals. This form of forgetting does not occur spontaneously, and may be reversed by administration of a prearranged signal without the reinduction of hypnosis, so it does not represent a form of state-dependent learning. The reversibility of amnesia indicates that its mechanisms are located at the retrieval stage of memory processing, rather than at the encoding or storage stages. Posthypnotic amnesia does not prevent words studied during hypnosis from being employed as free associates or category instances, indicating that posthypnotic amnesia is a disruption of episodic, but not semantic, memory. Moreover, the production of studied items as instances and associates is actually facilitated, resulting in priming effects. Similarly, posthypnotic amnesia does not affect retroactive inhibition or savings in relearning. Skills acquired during hypnosis are preserved afterward, even though the subject cannot remember the acquisition trials. This assortment of findings indicates that while posthypnotic amnesia disrupts explicit expressions of episodic memory (such as recall), it spares implicit expressions.

Other phenomena of hypnosis can also be understood in terms of the explicit-implicit distinction. For example, hypnotizable individuals who are given suggestions for deafness deny hearing anything; yet they show speech dysfluencies under conditions of delayed auditory feedback. And when given suggestions for blindness they deny seeing anything, yet show priming effects from stimuli presented in their visual fields. Based on an analogy between explicit and implicit memory, we may say that hypnotic suggestions for blindness, deafness, and the like impair explicit perception, while sparing implicit perception.

Professional Societies

Hypnosis is now a thriving topic for both scientific inquiry and clinical application, and is represented by such professional organizations as the Society for Clinical and Experimental Hypnosis, the American Society of Clinical Hypnosis, and other affiliates of the International Society of Hypnosis. The American Psychological Association has a special Division (Division 30, Psychological Hypnosis), devoted to hypnosis research and practice.

Professional Journals

The International Journal of Clinical and Experimental Hypnosis, the American Journal of Clinical Hypnosis, the Australian Journal of Clinical and Experimental Hypnosis, and Contemporary Hypnosis (formerly the British Journal of Experimental and Clinical Hypnosis are among the leading journals publishing hypnosis research.



This article is derived from "Hypnosis and the Psychological Unconscious", by J.F. Kihlstrom, which appeared in the Encyclopedia of Mental Health, Vol. 2, pp. 467-477 (Academic Press, 1998). The point of view represented in this article is based on research supported by Grant #MH-35856 from the National Institute of Mental Health.

Illustration Notes

Charcot hypnotizes a patient in his clinic, from Henri Ellenberger's The Discovery of the Unconscious (1970).

Recommended Reading

Bowers, K.S. (1976). Hypnosis for the seriously curious. Monterey, Ca.: Brooks/Cole.

Covino, N., & Frankel, F.H. (1993). Hypnosis and relaxation in the medically ill. Psychotherapy & Psychosomatics, 60, 75-90.

Fromm, E., & Nash, M.R. (Eds.) (1992). Contemporary hypnosis research. New York: Guilford.

Gauld, A. (1992). A history of hypnotism. Cambridge, U.K.: Cambridge University Press.

Hilgard, E.R. (1965). Hypnotic susceptibility. New York: Harcourt, Brace, & World.

Hilgard, E.R. (1977). Divided consciousness: Multiple controls in human thought and action. New York: Wiley-Interscience.

Hilgard, E.R., & Hilgard, J.R. (1975). Hypnosis in the relief of pain. Los Altos, Ca.: Kaufman.

Kirsch, I., Montgomery, G., & Sapirstein, G. (1995). Hypnosis as an adjunct to cognitive-behavioral psychotherapy: A meta-analysis. Journal of Consulting & Clinical Psychology, 63, 214-220.

Lynn, S.J., & Rhue, J.W. (Eds.) (1991). Theories of hypnosis: Current models and perspectives. New York: Guilford.

Olness, K., & Gardner, G.G. (1988). Hypnosis and hypnotherapy with children. 2nd ed. Philadelphia: Grune & Stratton.

Rhue, J.W., Lynn, S.J., & Kirsch, I. (Eds.) (1993). Handbook of clinical hypnosis. Washington, D.C.: American Psychological Association.

Sheehan, P.W., & Perry, C.W. (1976). Methodologies of hypnosis: A critical appraisal of contemporary paradigms of hypnosis. Hillsdale, N.J.: Erlbaum.

Spiegel, H., & Spiegel, D. (1978). Trance and treatment: Clinical uses of hypnosis. Washington, D.C.: American Psychiatric Press.


Episodic Memory -- memory for personal experiences, each associated with a unique spatiotemporal context; see contrasting Semantic Memory.

Explicit Memory -- conscious recollection, as manifested in the person's ability to recall or recognize some past event; see contrasting Implicit Memory.

Hypnotizability -- individual differences in response to hypnosis, as measured by standardized psychological tests such as the Stanford Hypnotic Susceptibility Scales.

Implicit Memory -- any effect on task performance which is attributable to a past event, independent of conscious recollection of that event; see contrasting Explicit Memory.

Priming -- the facilitation of perceptual-cognitive processing of a stimulus (known as a target) by presentation of a prior stimulus (known as a prime). In repetition priming, prime and target are identical (e.g., water-water); in semantic priming, prime and target are related in terms of meaning (e.g., ocean-water).

Semantic Memory -- context-free memory for factual information; see contrasting Episodic Memory.


John F. Kihlstrom, PhD

Copyright 2000 Institute for the Study of Healthcare Organizations & Transactions

Last modified:  04.08.2010 02:58 PM