Harvard Group Scale of Hypnotic Susceptibility – Form A

1. Abstract

The Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A), developed by Ronald E. Shor and Emily Carota Orne in 1962, represents one of the most widely utilized and thoroughly validated psychometric instruments in experimental hypnosis and cognitive neuropsychology. Adapted directly from the individually administered Stanford Hypnotic Susceptibility Scale, Form A (SHSS:A) by André M. Weitzenhoffer and Ernest R. Hilgard (1959), the HGSHS:A was engineered to overcome the resource-intensive requirements of individual testing by enabling standardized group administration paired with an objective, self-report behavioral scoring methodology. Comprising 12 standardized test suggestions following a progressive hypnotic induction procedure, the instrument systematically measures ideomotor responses, challenge catalepsies, cognitive-perceptual distortions, and post-hypnotic phenomena. Specifically, the scale evaluates motor automatisms (e.g., head falling, hand lowering, hands moving together), motor challenge catalepsies (e.g., arm immobilization, finger lock, arm rigidity, communication inhibition, eye catalepsy), sensory hallucination (experiencing of a fly), and post-hypnotic cognitive modifications (post-hypnotic response and post-hypnotic amnesia). Each item is evaluated via a dichotomous criterion (Passed = 1, Failed = 0), yielding an aggregate hypnotic susceptibility score spanning from 0 to 12. Psychometric evaluations across diverse international populations demonstrate solid internal consistency, with Kuder-Richardson Formula 20 (KR-20) and Cronbach’s alpha coefficients consistently ranging between .80 and .89, along with robust four-to-eight-week test-retest reliability estimates between .82 and .88. The scale demonstrates profound concurrent validity, correlating strongly (r = .60 to .85) with subsequent individual laboratory assessments on the Stanford scales (Forms B and C), thereby serving as the premier screening instrument for basic cognitive neuroscience, experimental psychopathology, and clinical trial stratifications.

2. Keywords

Harvard Group Scale of Hypnotic Susceptibility, HGSHS:A, hypnotic susceptibility, hypnotizability, ideomotor suggestion, challenge catalepsy, post-hypnotic amnesia, Stanford Hypnotic Susceptibility Scale, experimental hypnosis, psychometrics

3. Authors

The Harvard Group Scale of Hypnotic Susceptibility, Form A was developed by:

• Ronald E. Shor, Ph.D. — Formerly of the Studies in Hypnosis Project, Department of Psychiatry, Harvard Medical School; and late Professor Emeritus of Psychology at the University of New Hampshire. Dr. Shor was a foundational figure in experimental hypnosis, famous for conceptualizing the dual-aspect theory of hypnosis, the role of generalized reality-orientation (GRO) fading, and empirical measurement methodologies.
• Emily Carota Orne — Institute of Experimental Psychiatry, Pennsylvania Hospital, and the Department of Psychiatry, University of Pennsylvania School of Medicine. A prominent researcher in social psychophysiology, cognitive psychology, and the standardizations of hypnotic diagnostic metrics alongside Martin T. Orne.

Historical inquiries and permissions regarding archival materials are traditionally managed through the Society for Clinical and Experimental Hypnosis (SCEH) and the International Society of Hypnosis (ISH), with the original distribution overseen by the Consulting Psychologists Press (CPP) and Mind Garden.

4. Purpose

The primary purpose of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) is to provide an efficient, standardized, psychometrically rigorous, and cost-effective screening procedure to evaluate individual differences in hypnotic responsiveness within group testing environments. Prior to the introduction of the HGSHS:A, researchers investigating the cognitive, physiological, and clinical dimensions of hypnosis relied almost exclusively on individual hypnotic protocols, such as the Stanford Hypnotic Susceptibility Scale, Forms A and B (Weitzenhoffer & Hilgard, 1959). While clinically invaluable, individual administrations required approximately 60 to 90 minutes of dedicated one-on-one testing by highly trained examiners. This methodological bottleneck severely constrained sample sizes in laboratory experiments, hindered large-scale normative studies, and introduced examiner-specific behavioral variance that threatened experimental reproducibility.

The HGSHS:A resolved this critical logistical barrier by adapting the verbatim induction and test items of the SHSS:A into an audio-recorded or rigorously scripted spoken group protocol, coupled with a standardized self-report response booklet. This enabled investigators to administer the scale simultaneously to dozens, or even hundreds, of participants under identical auditory and temporal constraints. By delegating the initial scoring of behavioral responses to the participants themselves via operationalized objective criteria (such as measuring the physical distance an arm dropped or a hand moved), Shor and Orne established a method that dramatically democratized hypnotic research while preserving an exceptionally high degree of psychometric fidelity.

In contemporary clinical and empirical applications, the HGSHS:A fulfills multiple indispensable functions:

• Screening and Laboratory Stratification: In cognitive neuroscience and cognitive psychology, investigators frequently need to contrast individuals exhibiting high hypnotic suggestibility (“highs,” scores 9–12) against those exhibiting low suggestibility (“lows,” scores 0–3). The HGSHS:A functions as an initial group filter to recruit individuals who are subsequently verified via advanced individual testing, such as the Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C).
• Clinical Trial Profiling: In behavioral medicine, pain management, and psychosomatic interventions, baseline hypnotic capacity often predicts treatment outcomes for hypnotic analgesia, procedural anxiety reduction, and irritable bowel syndrome (IBS) hypnotherapy protocols. The HGSHS:A allows clinical researchers to assess whether therapeutic outcomes correlate directly with trait hypnotizability or are mediated by general expectancy and placebo mechanisms.
• Investigation of Cognitive and Perceptual Phenomena: The scale serves as a baseline psychometric index for studies exploring executive control, functional dissociation, default mode network (DMN) modulation, error-related negativity (ERN), attentional orienting, and conversion hysteria analogs.

5. Psychological Construct

The construct assessed by the HGSHS:A is hypnotic susceptibility (frequently termed hypnotizability or hypnotic suggestibility). In modern psychological measurement, hypnotizability is conceptualized as a stable, cognitive-behavioral trait characterized by an individual’s ability to experience suggested alterations in physiology, sensory perception, emotional state, motor control, memory, and subjective agency following an induction of hypnosis. It does not reflect general gullibility, neurotic compliance, or gullible persuasibility, but rather an innate capacity for attentional absorption, mental imagery engagement, and the temporary attenuation of metacognitive self-monitoring.

The HGSHS:A systematically captures this construct across several distinct behavioral and cognitive domains:

Motor Ideomotor Automatisms (Direct Suggestions)

Direct ideomotor suggestions measure involuntary motoric behaviors executed without conscious volitional effort. In these suggestions, the participant is instructed to imagine an external force or physical sensation acting upon their body, which naturally evokes the behavioral movement:

• Head Falling (Item 1): Evaluates postural instability and motor surrender as the head falls forward by at least two inches in response to repetitive suggestions of heaviness.
• Eye Closure (Item 2): Assesses involuntary closing of the eyelids driven by fatigue suggestions, serving as an initial index of receptive somatic relaxation.
• Hand Lowering (Item 3): Measures the downward descent of the outstretched left hand by at least six inches under the imagined burden of a heavy weight or gravity.
• Hands Moving Together (Item 7): Evaluates lateral horizontal movement, requiring the outstretched hands to converge inward by at least six inches due to imagined magnetic attraction.

Challenge Catalepsies (Motor Inhibition Suggestions)

Challenge items assess the participant’s subjective inability to initiate a normal motor act following an explicit verbal challenge from the hypnotist. These items evaluate inhibitory motor control and the dissociation of intent from motor execution:

• Arm Immobilization (Item 4): The participant is told their right arm is heavy, leaden, and glued to their lap or chair arm, followed by a direct challenge to lift it. Passing requires an inability to lift the arm at least one inch.
• Finger Lock (Item 5): Following interlocking of the hands, suggestions emphasize that the fingers are tightly bound and clamped together. The participant is challenged to separate them, scoring a pass if the hands fail to fully disengage.
• Arm Rigidity (Item 6): The left arm is suggested to be completely stiff and unbending like an iron bar, challenged to bend. A pass occurs when the arm bends less than two inches.
• Communication Inhibition (Item 8): Evaluates speech/gestural paralysis where the individual is challenged to shake their head “no” to indicate they cannot shake it. A pass occurs when the individual cannot execute the head movement.
• Eye Catalepsy (Item 10): The eyelids are suggested to be tightly glued shut, challenged to open them. The item is passed if the eyelids remain fully closed.

Cognitive-Perceptual Alterations and Somatosensory Hallucination

Unlike motor items, cognitive items evaluate alterations in sensory perception and mental simulation:

• Experiencing of Fly (Item 9): The hypnotist introduces an imaginary fly buzzing around the participant’s face, landing on the forehead or nose. The participant passes if they experience tickling, hear humming, feel involuntary muscle twitches, or exhibit a motor urge to brush the non-existent insect away.

Post-Hypnotic and Memory Control Phenomena

These complex items evaluate executive control over memory retrieval and delayed execution of behavioral cues outside the formal hypnotic context:

• Post-Hypnotic Suggestion (Item 11): The individual is instructed that upon hearing a specific auditory cue (a distinct pencil tap) after termination of the trance state, they will experience a compelling urge to touch their left ankle. Passing requires actual execution or an unmistakable conscious urge to execute the behavior.
• Post-Hypnotic Amnesia (Item 12): Assesses temporary retrieval failure. The participant is given a post-hypnotic suggestion that they will be unable to recall any of the events of the session until receiving an explicit release cue (“Now you can remember everything!”). Passing is operationalized as freely recalling three or fewer of the previous eleven items prior to the presentation of the release cue.

6. Theoretical Framework

The construction and validation of the HGSHS:A are grounded in major mid-twentieth-century psychological paradigms of hypnosis, primarily the neo-dissociation framework, socio-cognitive theories, and Dr. Ronald Shor’s three-factor theoretical model of hypnotic phenomena.

Shor’s Three-Dimensional Model

Ronald Shor proposed that hypnotic depth cannot be reduced to simple suggestibility alone, but is governed by three distinct structural dimensions:

1. Hypnotic Role-Taking Involvement: The extent to which an individual can willingly participate in the dramatic, psychological, and behavioral enactment of being hypnotized, integrating subjective imagination with contextual expectations.
2. Trance Depth (The Fading of the Generalized Reality-Orientation [GRO]): The cognitive process wherein an individual’s continuous, non-conscious background framework of reality orientation (which situates the self in time, space, and objective reality) fades into psychological abeyance. As the GRO recedes, suggested primary-process imagery becomes the subject’s prevailing experiential reality.
3. Archaic Involvement: The depth of primitive, transferential rapport established between the subject and the hypnotist, involving pre-rational compliance and dynamic emotional reliance.

The HGSHS:A was deliberately structured to tap directly into the second dimension (the suspension of the GRO) by delivering highly structured, rhythmic suggestions that progressively replace baseline contextual reality with suggested sensory constructs.

Hilgard’s Neo-Dissociation Theory

Ernest R. Hilgard (1977, 1986) formulated the neo-dissociation theory, conceptualizing human cognition as a hierarchical architecture of autonomous cognitive control systems monitored by an executive central processor. In Hilgard’s framework, hypnotic induction disrupts normal executive integration, establishing an amnesic or functional barrier between cognitive subsystems. Under this model:

• Ideomotor suggestions (e.g., hand lowering) occur because subsystem activation triggers motor output directly, while cognitive monitoring of self-volition is dissociatively blocked.
• Challenge catalepsies occur because the subsystem controlling the motor challenge is functionally isolated from the executive initiation pathways, creating the genuine experiential conviction of physical paralysis.
• Post-hypnotic amnesia represents a classic reversible dissociation where retrieval pathways are temporarily blocked at the executive interface until the associative release cue restores normal mnemonic access.

Socio-Cognitive and Cold Control Theories

In contrast to state-dissociative perspectives, socio-cognitive theorists (such as Nicholas Spanos and Theodore Sarbin) conceptualize HGSHS:A scores as reflections of goal-directed social compliance, active cognitive role enactment, and response expectancies. Modern cognitive models, particularly Zoltan Dienes’s Cold Control Theory of Hypnosis, integrate these viewpoints by asserting that hypnotic responding involves normal motor and cognitive actions executed with an absence of higher-order thoughts (HOTs) regarding the intention to act. Consequently, the individual performs the behavior while sincerely experiencing it as an involuntary phenomenon.

7. Validity

Extensive psychometric investigations over six decades have firmly established the construct, criterion, convergent, and discriminant validity of the HGSHS:A across multiple clinical and cross-cultural populations.

Concurrent and Criterion Validity

The primary benchmark for evaluating the HGSHS:A is its ability to accurately mirror individual hypnotic responsiveness measured on the gold-standard Stanford Hypnotic Susceptibility Scale, Form A (SHSS:A) and Form C (SHSS:C). In Shor and Orne’s (1962, 1963) initial normative standardization on university undergraduates, the correlation between group self-report scores on the HGSHS:A and subsequent individual assessments on the SHSS:A ranged from r = .71 to r = .83. Subsequent investigations by Bentler and Hilgard (1963) confirmed that self-scored group performance reliably predicts trained examiner objective scoring, with item-by-item agreement rates exceeding 85% across all motor items.

Convergent Validity

The HGSHS:A demonstrates strong positive correlations with other validated hypnotizability batteries:

• Stanford Hypnotic Clinical Scale (SHCS): Correlations consistently reach r = .65 to .78.
• Barber Suggestibility Scale (BSS): Moderate to high correlations (r = .55 to .72) are found with Barber’s direct waking and hypnotic suggestibility measures.
• Tellegen Absorption Scale (TAS): Hypnotizability as measured by the HGSHS:A correlates moderately (r = .30 to .45) with the TAS, supporting the theoretical link between hypnotic responsiveness and the personality trait of imaginative and sensory absorption (Tellegen & Atkinson, 1974).

Discriminant Validity

Importantly, research has firmly established that HGSHS:A scores do not reflect non-specific compliance, general gullibility, or neuroticism:

• Social Desirability: Correlations between the HGSHS:A and the Marlowe-Crowne Social Desirability Scale are uniformly non-significant (r = -.06 to .08), demonstrating that high scores do not stem from social pleasing or acquiescence bias.
• Five-Factor Model (Big Five): Hypnotizability shares negligible variance with Neuroticism, Extraversion, Conscientiousness, and Agreeableness (all rs < .10). It demonstrates a selective, weak-to-moderate association with Openness to Experience (r = .15 to .25), specifically within the fantasy and aesthetic appraisal subfacets.
• General Intelligence: Scores on the HGSHS:A are uncorrelated with IQ measures or general cognitive aptitude, demonstrating that hypnotic responsiveness operates independently of general mental capacity.

8. Reliability

The HGSHS:A demonstrates high internal consistency and stability over extended temporal intervals.

Internal Consistency

Because the HGSHS:A items are dichotomously scored (0 or 1), internal consistency is primarily evaluated utilizing the Kuder-Richardson Formula 20 (KR-20), which is mathematically equivalent to Cronbach’s alpha for binary data:

• In the original normative sample of 132 participants, Shor and Orne (1963) reported a KR-20 reliability coefficient of .80.
• In an expanded replication sample of 383 undergraduates, the internal consistency was established at KR-20 = .83.
• International normative studies across several decades have reinforced these findings: Bongartz (1985) reported an alpha of .81 in a German sample (N = 558); Lamas, del Valle-Inclán, Blanco, and Díaz (1989) found an alpha of .82 in a Spanish standardization (N = 649); and Green, Lynn, and Malanos (2005) reported an alpha of .84 in a large modern North American cohort (N = 1,027).

Test-Retest Stability

Hypnotic susceptibility as evaluated by the HGSHS:A is remarkably stable across the adult lifespan:

• Short-to-medium term test-retest reliability across intervals of two to eight weeks yields Pearson correlation coefficients ranging from r = .82 to r = .89.
• Remarkably, longitudinal investigations tracking individuals over multi-decade intervals (e.g., Morgan, Johnson, & Hilgard, 1974; Piccione, Hilgard, & Zimbardo, 1989) have demonstrated that hypnotic susceptibility assessed via Stanford and Harvard instruments exhibits test-retest stability coefficients exceeding r = .60 over intervals as long as 10 to 25 years. This stability is comparable to the most enduring personality traits, such as those measured by the Big Five inventory.

9. Factor Analysis

Although the HGSHS:A was originally constructed by Shor and Orne (1962) as a unidimensional Guttman-like scale measuring progressive hypnotic depth, subsequent exploratory factor analyses (EFA) and confirmatory factor analyses (CFA) have consistently revealed an underlying multidimensional structure.

Exploratory Factor Analyses

Seminal factor-analytic investigations by Peters, Hilgard, and Stern (1973), as well as subsequent analyses by Kirsch, Silva, Carone, Leahey, and Bellingham (1995), delineated two to three primary factors:

• Factor 1: Direct Ideomotor / Motor Involuntary (Positive Response): Primarily loaded by Item 1 (Head Falling), Item 3 (Hand Lowering), and Item 7 (Hands Moving Together). This factor captures dynamic motor facilitation driven by external suggestions. Item loadings typically range from .55 to .78.
• Factor 2: Motor Challenge / Inhibitory Catalepsy: Loaded heavily by Item 4 (Arm Immobilization), Item 5 (Finger Lock), Item 6 (Arm Rigidity), Item 8 (Communication Inhibition), and Item 10 (Eye Catalepsy). This factor captures the subject’s inability to overcome suggested motor blocks. Item factor loadings range between .52 and .74.
• Factor 3: Cognitive / Dissociative / Post-Hypnotic: Captured by Item 9 (Fly Hallucination), Item 11 (Post-Hypnotic Suggestion), and Item 12 (Post-Hypnotic Amnesia). Item 12 (Amnesia) often demonstrates a distinct structural isolation, showing lower correlation with standard motor items and representing a purely cognitive retrieval blockage.

Confirmatory Factor Analysis and Model Fit

Modern psychometric re-examinations (e.g., Woody, Barnier, & McConkey, 2005; Sadler & Woody, 2003) utilizing robust categorical estimation methods (WLSMV) have systematically compared unidimensional, two-factor, and three-factor models:

• Unidimensional Model: Demonstrates acceptable yet suboptimal fit indices (e.g., Root Mean Square Error of Approximation [RMSEA] ≈ .072; Comparative Fit Index [CFI] ≈ .88; Tucker-Lewis Index [TLI] ≈ .86), indicating that a single omnibus hypnotizability factor fails to capture subtle construct variations.
• Hierarchical Three-Factor Model: A higher-order structure featuring three first-order factors (Ideomotor, Challenge, Cognitive-Amnesic) subordinated to a general “Hypnotizability” macro-factor consistently yields superior fit indices: RMSEA = .038 (90% CI [.024, .051]), CFI = .962, TLI = .954, and SRMR = .045.

These findings validate the operational utility of computing an overall total score (0–12) for screening purposes, while confirming the presence of distinct neurocognitive facets (motor facilitation, motor inhibition, and cognitive alteration) for specialized experimental investigations.

10. Instrument / Measurement Tool

The Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) is an objective behavioral self-report instrument administered following a standardized hypnotic induction.

• Test Type: Standardized group performance test utilizing retrospective objective self-scoring.
• Format: Written response booklet administered immediately following a live or recorded audio hypnotic induction and suggestion protocol.
• Number of Items: 12 standardized test items.
• Administration Time: Approximately 45 to 55 minutes total (30–35 minutes for induction and suggestion administration; 10–15 minutes for response booklet completion).
• Response Scale: Dichotomous self-scoring criterion (Passed = 1, Failed = 0) based on objective behavioral criteria and response options in the self-report response booklet.
• Scoring and Normative Stratification:
  • Total Score Calculation: Total score ranges from 0 to 12, calculated by summing the number of items passed according to the objective behavioral criteria specified in the self-report response booklet (items scored 1 if criterion was met, 0 if not). Amnesia (Item 12) is scored 1 if fewer than 4 items are remembered prior to the reversal cue.
  • Susceptibility Classifications:
    • Low Hypnotizability: 0 – 3 items passed (bottom ~20% of normative distributions).
    • Medium Hypnotizability: 4 – 8 items passed (middle ~60% of normative distributions; mean typically falls around 6.5 – 7.2).
    • High Hypnotizability: 9 – 12 items passed (top ~20% of normative distributions).

11. Permissions & Fee and Test Year

The Harvard Group Scale of Hypnotic Susceptibility, Form A was first formalized and published in 1962 (norms published in 1963) by Ronald E. Shor and Emily Carota Orne. The instrument was historically distributed in physical format by the Consulting Psychologists Press (Palo Alto, CA) and later archived via specialized psychological research distribution outlets such as Mind Garden, Inc.

For scientific, academic, and non-commercial educational research, the script, test protocol, and response booklet have been widely reprinted in peer-reviewed literature, theoretical handbooks, and clinical compendiums. While the text of the suggestions and scoring booklets is technically under historical copyright by the original authors and publishers, reasonable non-commercial academic research utilization is broadly permitted under fair academic use frameworks or by contacting the archival copyright holders (the Society for Clinical and Experimental Hypnosis or the Orne family academic trusts). Commercial application, electronic reproduction for commercial software, or fee-for-service clinical platform integration requires explicit licensing permission from the designated copyright proprietors.

12. References

• Bentler, P. M., & Hilgard, E. R. (1963). A comparison of group and individual administration of adult hypnotic susceptibility scales. International Journal of Clinical and Experimental Hypnosis, 11(4), 209–216. https://doi.org/10.1080/00207146308409247
• Bongartz, W. (1985). German norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A. International Journal of Clinical and Experimental Hypnosis, 33(2), 131–139. https://doi.org/10.1080/00207148508406643
• Green, J. P., Lynn, S. J., & Malanos, C. E. (2005). Identifying hypnotic ability: An evaluation of the Harvard Group Scale of Hypnotic Susceptibility, Form A. International Journal of Clinical and Experimental Hypnosis, 53(3), 259–278. https://doi.org/10.1080/00207140590961358
• Hilgard, E. R. (1977). Divided consciousness: Multiple controls in human thought and action. John Wiley & Sons.
• Hilgard, E. R. (1986). Hypnotic susceptibility. Harcourt, Brace & World.
• Kirsch, I., Silva, C. E., Carone, J. E., Leahey, T. C., & Bellingham, P. J. (1995). The prediction of response to subjective and behavioral suggestions: A confirmatory factor analysis. Journal of Personality and Social Psychology, 68(6), 1147–1155. https://doi.org/10.1037/0022-3514.68.6.1147
• Lamas, J. R., del Valle-Inclán, F., Blanco, M. J., & Díaz, R. (1989). Spanish norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A. International Journal of Clinical and Experimental Hypnosis, 37(4), 338–348. https://doi.org/10.1080/00207148908414486
• Morgan, A. H., Johnson, D. L., & Hilgard, E. R. (1974). The stability between childhood and adulthood of hypnotic susceptibility as measured on the Stanford Hypnotic Susceptibility Scales. International Journal of Clinical and Experimental Hypnosis, 22(3), 249–257. https://doi.org/10.1080/00207147408413004
• Peters, J. E., Hilgard, E. R., & Stern, J. A. (1973). The factor structure of the Harvard Group Scale of Hypnotic Susceptibility, Form A. International Journal of Clinical and Experimental Hypnosis, 21(2), 95–102. https://doi.org/10.1080/00207147308409838
• 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), 289–295. https://doi.org/10.1037/0022-3514.56.2.289
• Sadler, P., & Woody, E. (2003). Is who you are what you get? A multidimensional approach to hypnotic suggestibility. International Journal of Clinical and Experimental Hypnosis, 51(2), 123–151. https://doi.org/10.1076/iceh.51.2.123.14613
• Shor, R. E., & Orne, E. C. (1962). Harvard Group Scale of Hypnotic Susceptibility, Form A. Consulting Psychologists Press.
• Shor, R. E., & Orne, E. C. (1963). Norms of the Harvard Group Scale of Hypnotic Susceptibility, Form A. International Journal of Clinical and Experimental Hypnosis, 11(1), 39–47. https://doi.org/10.1080/00207146308409226
• Tellegen, A., & Atkinson, G. (1974). Openness to absorbing and self-altering experiences (“absorption”), a trait related to hypnotic susceptibility. Journal of Abnormal Psychology, 83(3), 268–277. https://doi.org/10.1037/h0036681
• Weitzenhoffer, A. M., & Hilgard, E. R. (1959). Stanford Hypnotic Susceptibility Scale, Forms A and B. Consulting Psychologists Press.
• Woody, E. Z., Barnier, A. J., & McConkey, K. M. (2005). Multiple hypnotizabilities: Differentiating the styles of response to hypnotic suggestions. Contemporary Hypnosis, 22(4), 169–177. https://doi.org/10.1002/ch.32

13. Items of the Scale