Hypnotic suggestibility testing has existed in some form since Mesmer popularized hypnosis in the latter 18th century. It was not until the mid 20th century, however, that it passed through the prism of scientific scrutiny. Hypnotic suggestibility is a somewhat controversial subject. There are some people who believe it is not necessary for hypnosis to be successful. There are others who believe it is an integral part of hypnosis, especially when using it for research and the treatment of certain issues. Here is what you need to know about hypnotic suggestibility testing:
What Is Hypnotic Suggestibility Testing?
Hypnotic suggestibility testing is an assessment done to find out your level of hypnotizability. Hypnotizability has been defined by APA Division 30 as “an individual’s ability to experience suggested alterations in physiology, sensations, emotions, thoughts, or behavior during hypnosis.”  There are various kinds of measures used to test suggestibility. Some measures are more scientifically based while others are very informal. For example, when using hypnosis for re-search purposes you will want to use a scientifically validated assessment measure, such as the Stanford scales. When using it for entertainment or certain clinical purposes, however, a single quick method, such as “magnetic hands” could be used. There are many fast and simple suggestibility tests that are used for non-research purposes. For example, when using “magnetic hands” the client is asked to imagine that their hands, which are facing each other a few inches apart, are being pulled together like magnets. For the purposes of this article, the term hypnotizability will be used inter-changeably with hypnotic suggestibility and hypnotic susceptibility.
Uses Of Hypnotic Suggestibility Testing
There are multiple reasons people use hypnotic suggestibility testing, including the following:
It Helps Select the Most Effective Hypnosis Method.
A hypnotist uses an induction to put you in a mental state that prepares you to be hypnotized.  Usually, an induction involves some form of relaxation. A client may be instructed to close their eyes and practice some deep breathing, for example. Because assessments use different types of inductions and suggestions (e.g., motor vs. cognitive) it gives the hypnotist insight into which types would help produce the most hypnotizable state. Additionally, it provides insight into whether the subject favors a permissive or authoritarian style from the hypnotist. Furthermore, clients usually prefer a certain modality of hypnotism. Suggestibility testing can help you find out if the subject is more visual, auditory, or kinesthetic.
It Provides a Warm Up
It is important that the client is in the proper frame of mind to help make hypnosis successful. A warm up assists the client in obtaining the proper focus. In addition, any anxiety that the client feels can be reduced by the testing; It helps them to get used to the process. Moreover, if the testing shows that a person is hypnotizable, it leads the subject to believe that hypnotism will work for them. As a result, they will have in-creased confidence in the procedure and it is more likely to be successful.
Suggestibility testing is often used for treatment and research purposes. There appears to be an interaction between hypnotic suggestibility and treatment outcome for certain types of problems. For example, in 2008, Milling found that the success of using hypnosis for pain reduction was dependent on how susceptible the person was to being hypnotized.The more hypnotizable the subject, the more pain reduction. Similar results have also been found in other hypnotic treatment studies on pain.
When dealing with other treatment issues, however, such as smoking cessation and obesity, the results are not as conclusive. In 2003, Lynn, Shindler and Meyer, did not find definitive evidence that the level of suggestibility was a factor in the treatment of issues besides pain management. It should be noted, however, that even at lower lev-els of suggestibility, there is little reason to believe that hypnosis cannot be an effective treatment modality.
How Do Hypnotic Suggestibility Tests Generally Work?
Tests usually begin with some rapport-building between hypnotist and subject. After some rapport is established, a simple induction takes place. The induction is followed by the test suggestions. Scales of hypnotic suggestibility usually contain test suggestions which are pass/fail. The items are designed to assess a range of hypnotic fields. Test suggestions are either motor or cognitive in nature. A positive mo-tor suggestion is an attempt to produce motor behavior. For example, it might be suggested that a subject’s head will rise without assistance. A negative motor suggestion would be attempting to inhibit motor action. For instance, it might be suggested that the subject will not be able to open their eyes. Cognitive suggestions attempt to produce or inhibit perceptions or sensations. An example of a positive cognitive suggestion would be a taste hallucination, such as tasting something sweet or sour. A negative cognitive suggestion might be a situation in which it is suggested that a participant cannot hear, otherwise known as hypnotic deafness.
The Importance of Involuntary Actions
For a suggestion to be a truly hypnotic experience, it should feel like it is involuntary. Any behavior that is voluntary in nature is not measuring hypnotic suggestibility. For example, let’s look at one of the examples from above. Say a test item suggests that your head is rising in the air without assistance. If your head feels like it is rising involuntarily, you are said to have passed the item. This is what is meant by involuntariness. Any voluntary attempt to raise your head causes you to fail the item.
Early Hypnotic Suggestibility Testing
Although assessment of hypnotic suggestibility was informally done in the 18th and 19th century, it was not until the 20th century that assessment measures were approached with an eye on scientific quality. For example, the White Scale, developed in 1930, although not hugely popular, had properties which would define future scales of hypnotizability. It was one of the first scales to measure one observable behavior. In addition, it placed items in order of increasing difficulty. The Davis and Husband Scale,  developed in 1931, was widely used and covered a wide range of hypnotic behaviors, but it lacked some validity. The major problem was that it did not include specific criteria to determine whether suggestions had been passed or failed.
The Friedlander-Sarbin Scale, introduced in 1938, had some of the features of the Davis-Husband and White scales, but it took a stronger step toward research respectability. It standardized procedures, items, and scoring. It also included a script for the induction process and a specific set of test suggestions with standardized scoring criteria. Unfortunately, even with improvements, it still lacked aspects of validity and reliability.
Stanford Hypnotic Susceptibility Scales
Weitzenhoffer and Hilgard took the Friedlander-Sarbin scale and improved upon it. They added less difficult items to spread out the distribution of scores. In addition, scoring was simplified and two different forms were created to permit repeated administration that would take into account practice effects. For example, differences in forms included similar suggestions that were slightly changed, such as using the opposite hand. The result was the Stanford Hypnotic Susceptibility Scale, Forms A & B (SHSS: A,B).
The first Stanford scales, A & B, although a major advance in the measurement of hypnotizability, had limited usefulness because they were made up of only motor items and did not take into account cognitive processes. Furthermore, it did not seem sensitive to differences among subjects.
In 1967, Weitzenhoffer and Hilgard improved upon their original Stanford Scales with Form C. The new version included items that more fully assessed the subject’s ability to experience cognitive processes, rather than just motor behaviors, during hypnosis. Form C also presented items in order of increasing difficulty, aiding in differentiating the level of hypnotizability between subjects. John F. Kihlstrom updated Scale C in 1996.
The SHSS spawned a host of other assessment measures. These include the Stanford Profile Scales of Hypnotic Ability, Forms I and II, which were designed to create a profile of good hypnotic subjects. The scales have also been adapted for clinical use with children.
Overview of the Stanford Hypnotic Susceptibility Scales
The SHSS A & B consist of 12 items that take up to an hour to complete. The items are arranged in progressing difficulty. Subjects are given a hypnotic induction, followed by different hypnotic suggestions. For example, one suggestion asks you to imagine your hand is so heavy that you cannot hold it up. If you can hold up your hand, you fail that item. Most people are able to perform the first few items but not many people make it to the end of the test. According to the scales, the farther you get, the more susceptible you are to hypnosis.
Scoring of the SHSS is as follows:
0-4 is considered a low level of suggestibility
5-7 is medium
8-12 is high
Form C has items that require movement (motor items), but also includes cognitive suggestions, such as hallucinations. These hallucinations relate to the senses of vision, taste and hearing. Form C also attempts to measure “hypnotic depth” and “posthypnotic suggestion”. It is not an overstatement to say that the SHSS is the most popular and most studied assessment measure of hypnotic suggestibility. It has also been found to be scientifically reliable, having a reliability index of .85, meaning that you can expect the same results upon repeated administration 85 percent of the time.
Harvard Group Scale of Hypnotic Susceptibility
One of the main issues with the Stanford Scales is the amount of time and resources that are needed for administration. They require a hypnotist to administer the scales one person at a time. As noted above, this process takes about an hour. As you might imagine, administering the SHSS to a large number of people can be quite cumber-some. This may prohibit research from occurring on large groups. Because the validity of research often requires a large sample size, it was important to create a measure that could assess hypnotic suggestibility in a more efficient manner.
In 1962, Shor & Orne developed the Harvard Group Scale of Hypnotic Susceptibility: Form A (HGSHS:A) to serve that purpose. It shares many of the same items as the SHSS but it is a self-report measure that can be administered to groups. While the HGSHS lends itself nicely to research, it brings up questions of reliability and validity; self-report measures usually does not hold up as well to scientific scrutiny.
Since the HGSHS was developed to be a more efficient option than the Stanford scales, you would expect a high correlation between tests. Unfortunately, the Harvard Scales only share a .60 correlation with the Stanford Scales, which suggests they are not exactly measuring the same elements of hypnotizability. While the HGSHS provides efficiency, it possesses some weaknesses when compared to the SHSS. Despite those concerns, the use of the HGSHS remains highly popular.
Factors Of Influence In Hypnotic Suggestibility Tests
Hypnotizability has long been thought to be an unchangeable trait. In psychology, this is referred to as a static trait. Indeed, there is research that suggests suggestibility re-mains stable over many years. Does this mean that there are no factors that could change one’s level of hypnotizability? Because hypnotic suggestibility may affect the results of hypnotism as a treatment modality, it seems important to find out if a person’s level of hypnotic suggestibility is modifiable. The following variables have been shown to impact the assessment of hypnotizability.
It does appear that hypnotizability is partially passed on through our genes. In 1973, Arlene Morgan conducted research on twins and found a higher level of heritability between identical twins than fraternal twins.
Oxytocin is a naturally occurring hormone in the body. Increases in oxytocin appear to improve suggestibility in clients. Recent research (Bryant and Hung, 2013) has concluded that oxytocin increases social persuasion in subjects during hypnosis, thus making a hypnotist more effective.
A good rapport between hypnotist and client also appears to boost suggestibility. This makes sense in that you are more likely to comply with someone’s request if you share a positive rapport with them. The above-mentioned study also found that rapport boosts oxytocin in the body, which would further open one to social persuasion.
In 1987, Auke Tellegen defined absorption as “a disposition, penchant, or readiness to enter states characterized by marked cognitive restructuring” and a “readiness to depart from more everyday life cognitive maps and to restructure also in the process one’s representation of one’s self and its boundaries”. In laymen’s terms, absorption is a per-son’s ability to be involved in a sensory or imaginary state. Absorption as a construct has been well studied and has shown a consistent association with hypnotizability.
Dissociation has been described as the ability to detach from your environment. When someone exhibits a lack of integration of mental processes, they may be described as being in a dissociative state. Dissociation has been linked to hypnotizability in the literature for many years. It is thought that the dissociative state lends itself nicely to being hypnotized, since they share many similarities. Indeed, some researchers have hypothesized that being in a dissociative state, at the very least, overlaps with the state of being hypnotized. In a 2015 study, Cleveland, Korman & Gold found a positive association between suggestibility and non-pathological dissociative states.
People with greater connectivity between the left and right hemisphere of the frontal cortex display higher levels of hypnotic suggestibility than those with less connectivity. This makes sense, since the frontal cortex is most often associated with the monitoring of one’s mental state.
The placebo effect is alive and well as a factor in treatment outcomes. It may play an even more integral role in hypnosis. If you believe that you are hypnotizable and that using hypnosis will lead to the desired treatment outcome, then you will exhibit in-creased hypnotizability. In their literature review in 2015, Mark Jensen at the University of Washington and his group of five fellow researchers from around the world, concluded that expectations do indeed play a role in hypnotic suggestibility, but their impact varies across interventions.
Numerous researchers have given subjects drugs to increase hypnotic suggestibility, with varying success. Alcohol, marijuana, and LSD have all shown promise in increasing hypnotizability. A significant problem with measuring the effects of drugs is that you do not know whether the change is due to the specific effect of the drug or simply due to a general feeling of being “high”. In addition, some of these drugs remain illegal in the United States.
There does appear to be some evidence that hypnotic suggestibility can be modified. Although some of the factors cited relate to static genetic and physiological variables, others are social and psychological in nature, and therefore, subject to change.
Challenges to Hypnotic Suggestibility Testing
Hypnotic vs. Non-hypnotic (Imaginative) Suggestibility.
A distinction has been made by certain researchers between hypnotic suggestibility and non-hypnotic suggestibility. Non-hypnotic suggestibility measures how people respond to a suggestion without hypnotic induction. Hypnotic suggestibility, on the other hand, is a response when induction is used. Since most of the popular scales of hypnotizability use induction, they would technically be measuring hypnotic suggestibility under the hypnotic framework.
So, why does this matter? There is research that suggests that people’s response to hypnotic suggestions is almost as strong without an induction as it is with one. In other words, subjects respond to suggestions even without hypnotic inductions. Therefore, induction may not have a significant effect. This brings up an important question: If induction is not important, what are all the suggestibility scales (that use induction) actually measuring?
Looking at the results of his research, Kirsch feels it would be more accurate to define hypnotizability as the difference between hypnotic and non-hypnotic (or imaginative) suggestibility. He believes that the operational definition currently used for hypnotizability is not supported by the research, therefore invalidating many assessment measures. Instead, he argues that hypnotizability is simply measuring a subjects’ expectations of the response rather than their true suggestibility to hypnosis. This puts into question whether hypnotic suggestibility testing is even necessary for hypnosis research.
The research on hypnotic and non-hypnotic suggestibility is a major challenge to the field of hypnotic suggestibility testing. The most popular scales (e.g., the SHSS) were developed before a difference between hypnotic and non-hypnotic suggestibility was ever explored in the research. If you believe that induction is not necessary to measure suggestibility, then scales that use induction are no longer valid201. It needs to be kept in mind, however, that there are many people in the field who do not adhere to the distinction between hypnotic suggestibility and non-hypnotic suggestibility and continue to support the use of traditional measurement scales, such as the SHSS and HGSHS.
Another challenge with suggestibility testing is that it may interfere with hypnosis, if it leads people to believe they are not hypnotizable. If a patient is given a suggestibility test and they score low, this may lead them to believe that they will not benefit from hypnotic treatment. This correlation may or may not exist, but the mere thought in the client’s mind that it may exist can cause it to exist. This is the essence of hypnotherapy – expectation becoming reality as a result of the existence of the expectation. Expectations matter, and if expectations of the effectiveness of hypnosis are questioned, that may lead to a lack of confidence in the hypnotic process. For this reason, I choose not to teach hypnotic suggestibility tests in my online hypnosis class.
Clinicians vs. Research
Hypnotic suggestibility testing is almost always used in hypnosis research. For clinical use, however, it is often ignored. As many clinicians will argue, it is not necessary for a client to be suggestible for hypnosis to be effective as a treatment method. Additionally, as noted above, suggestibility scales are time-consuming and not practical for most clinical purposes.
These opinions once again raise the question: If hypnotic suggestibility scales are not needed for clinical use, are they really that important? While formal testing for suggestibility may not be worth the effort for most clinical work, it still appears to be valuable for research. In 2017, Jensen and his fellow researchers stated that “in experimental contexts, hypnotic suggestibility is more strongly and more consistently predictive of responsiveness to suggestion” than when it is used for clinical purposes.
Hypnotism Is Not Taken Seriously
Despite a fair amount of research that shows the efficacy of hypnotism, the general public at large still believes that hypnotism is not based on serious science. The depiction of hypnosis in popular culture certainly does not help. Because of its portrayal, there are professionals that avoid and ignore the subject of hypnosis. This leads to a lack of research and funding to further examine the role of hypnotic suggestibility assessment and its correlates. As a result, professionals continue to use measures that are over 50 years old. Jensen and his colleagues in 2017 noted that new measures of hypnotic suggestibility testing would be beneficial for measuring “distortions in body image, time perception, and sensorimotor integration”. Overall, however, there is not much research into hypnosis when compared with other areas of psychological study. Hypnotic suggestibility testing will ultimately suffer without a renewed interest in the field of hypnosis.
Find Out How Suggestible You Are
My hypnotic suggestibility test is adapted from the Stanford Hypnotic Susceptibility test. It has not been checked for correlation to the original test, but, based on my experience and knowledge of these tests, I feel it will give you a good idea of how suggestible you are.
There are seven questions. Answer each of them to the best of your ability. Afterward, you will be able to see your test score.
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- ^ Whalley, M. (2007). Definitions of Hypnosis and Suggestion.
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- ^ Spanos, N. P., Radtke-Bodorik, H. L., Ferguson, J. D., & Jones, B. (1979). The effects of hypnotic susceptibility, suggestions for analgesia, and the utilization of cognitive strategies on the reduction of pain. Journal of Abnormal Psychology, 88(3), 282-292.
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- ^ Council J.R., (2002) A Historical Overview of Hypnotizability Assessment. American Journal of Clinical Hypnosis 44, 3/4.
- ^ Weitzenhoffer, A. M., Higard, E. R. (1962). Stanford Hypnotic Suggestibility Scale: Forms C. Consulting Psychologists Press, Palo Alto, California, USA.
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- ^ Evans, F. J., & Schmeidler, D. (1966). Relationship between the Harvard Group Scale of Hypnotic Suggestibility and the Stanford Hypnotic Suggestibility Scale: Form C. Inter-national Journal of Clinical and Experimental Hypnosis, 14(4), 333-343.
- ^ Piccione, C., Hilgard, E.R., & Zimbardo, P.G. (1989). On the degree of stability of measured hypnotizability over a 25-year period. Journal of Personality and Social Psychology 56 (2), 289-95.
- ^ Morgan, A.H. (1973) The heritability of hypnotic suggestibility in twins. Journal of Ab-normal Psychology 82(1), 55-61.
- ^ Bryant R.A. & Hung, L (2013). Oxytocin Enhances Social Persuasion during Hypnosis. Plos One 8(4).
- ^ Tellegen, A. (1987). Discussion of symposium: Hypnosis and absorption. Paper presented at the 38th Annual Meeting of the Society for Clinical and Experimental Hypnosis, Los Angeles
- ^ Nadon, R., Hoyt, I.P., Register, P.A. & Kihlstrom, J.E. (1991) Absorption and Hypnotizability: Context Effects Reexamined. Journal of Personality and Social Psychology 60 (1), 144-153.
- ^ Quant, M.B. (2015). Hypnotic Suggestibility of Inpatient Adolescents.
- ^ Cleveland, J., Korman, B. & Gold, S. (2015). Are Hypnosis and Dissociation Related? New Evidence for a Connection. International Journal of Clinical and Experimental Hypnosis. 63,198-214.
- ^ Jensen M.P., Adachi T, Tomé-Pires C, Lee J, Jamil Osman Z, Miró J. (2015) Mechanisms of hypnosis: toward the development of a biopsychosocial model. International Journal of Clinical and Experimental Hypnosis, 63, 34–75.
- ^ Kirsch, I., & Braffman, W. (2001). Imaginative Suggestibility and Hypnotizability. Current Directions in Psychological Science, 10(2), 57–61.
- ^ Jensen, M.P., Jamieson, G.A., Lutz, A, Mazzoni, G, McGeown, W.J., Santarcangelo, E.L., Demertzi, A., De Pascalis, V., Bányai, E.I., Rominger, C., Vuilleumier, P. Fay-monville, M., Terhune, D.B. (2017) New directions in hypnosis research: strategies for advancing the cognitive and clinical neuroscience of hypnosis, Neuroscience of Consciousness, Volume 2017, 1.