Montréal norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A

French Norms for a Shortened Online Adaptation of the Harvard Group Scale of Hypnotic Susceptibility, Form A

This study presents the norms and psychometric properties for a shortened online adaptation of a French version of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A). Assessment of involuntariness and subjective intensity was added to the traditional scoring. A total of 373 individuals completed an online hypnotizability screening test on their own computer. Participants received the HGSHS:A script through an audio recording lasting about 30 minutes. The results showed that the item difficulty and reliability of the short online HGSHS:A were consistent with the offline version of the scale and with the reference samples. Involuntariness and subjective intensity corrections improved significantly the accuracy in the measurement of the scale and helped to dissociate between different phenomenologies in hypnotic responding. These findings indicate that the short online HGSHS:A is a reliable tool for measuring hypnotizability. Moreover, we suggest that using complementary measures of involuntariness and subjective intensity helps to shed more light on hypnotizability as part of a multi-componential approach to hypnotic response.

Hypnotizability Norms may not be Representative of the General Population: Potential Sample and Self-Selection Bias Considerations

The analysis of the methods sections of 66 normalization tests of hypnotizability scales reveals that out of 33,338 subjects, 58.57% were college and university students, and the majority of these were students of psychology. Of all subjects, 7.45% were younger school children, 27.63% were patients treated with hypnosis, and out of these, 85.26% were patients of 1 single therapist. Only 0.51% were trainees of dental or nursing schools, 0.13% were prisoners, and 5.71% were other adults. These figures suggest a sample-selection bias. As 83.08% of these subjects were told beforehand that they were to undergo a hypnosis study, a self-selection bias is also implied in the data. It can be presumed that those interested in hypnosis participated, whereas others who had no interest in hypnosis may have refrained. It is concluded that some of the published norms of hypnotizability tests may not be adequately representative of the general population. Many hypnosis studies, whether clinical or experimental, which are based on hypnotizability, may be afflicted by these biases.

German Norms of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) and Proposal of a 5-Item Short-Version (HGSHS-5:G)

The Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A), is commonly used to test hypnotizability. There is still some controversy about what exactly hypnotizability is and whether and how it can be measured, especially by the HGSHS:A. Furthermore, a wider clinical use is limited, requiring a testing time of more than 1 hour. We analyzed the German HGSHS:A version for its factorial structure, item contribution, and item difficulty based on test data from six studies, including 1276 persons, to propose a shorter version of the HGSHS:A. We hereby present a 5-item version of the HGSHS:A (HGSHS-5:G), consisting of the challenge items, that was compared with an 11-item version (highly variable posthypnotic amnesia omitted). Age- and gender-specific norms was generated. The HGSHS-5: G showed high validity, reliability, and classification agreement. It reduces test time to 30 minutes thus facilitating wider use of hypnotizability testing.

Hypnotised by Your Phone? Smartphone Addiction Correlates With Hypnotisability

Hypnosis and heavy smartphone use are both characterised by absorbed states in which one loses track of time and responds automatically to stimuli. In this pre-registered study, we tested whether there was a relationship between smartphone addiction and hypnotisability: one's tendency to follow suggestions under hypnosis. Over 11 public lectures, we hypnotised 641 student-aged participants; after the hypnosis session, participants completed the Smartphone Addiction Scale (Short Version). There was a positive correlation between hypnotisability and smartphone addiction (r = .17, 95% CI [.09, .24], p < .001) with a magnitude similar to standard predictors of hypnotisability. This correlation was small but unlikely spurious: it was positive in 10 of the 11 samples (including two from psychology courses) and persisted in a follow-up several months later. The addiction scores in this Canadian sample were unexpectedly high (M = 31.41) compared to other countries. We hypothesise that targeting the absorbed, time-distorted, and automatic use of smartphones may promote healthier phone habits.

UNITED KINGDOM NORMS FOR THE HARVARD GROUP SCALE OF HYPNOTIC SUSCEPTIBILITY, FORM A

The Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A), is widely used as a measure of suggestibility to screen participants for research purposes. To date, there have been a number of normative studies of the HGSHS:A, the majority of which originate from Western countries. The outcomes of these Western studies are summarized, and variations in methodologies are described and discussed. Also reported are the psychometric properties of the HGSHS:A in a large contemporary United Kingdom (UK) sample. Overall, these UK results are consistent with the earlier Western norms studies in terms of response distribution and item difficulty, with only minor differences. The continued use of HGSHS:A as a screening procedure is supported, particularly if corrected for response subjectivity/involuntariness and with revised amnesia scoring. The HGSHS:A is also important as a potential measure of the broader trait of direct verbal suggestibility.

TAIWANESE NORMS FOR THE HARVARD GROUP SCALE OF HYPNOTIC SUSCEPTIBILITY, FORM A

Hypnotic susceptibility is a fundamental individual characteristic to consider in studies examining hypnosis. Although there is no existing normative data of group hypnotic susceptibility tests for the Mandarin-speaking Chinese population, the current study administered the Mandarin Chinese translation of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) to 242 subjects (137 females and 105 males). The results indicate that the normative properties-including the score distribution, item pass rates, and reliability-are comparable to 15 reference samples. In general, the Mandarin Chinese version of the HGSHS:A can be used as a viable and reliable instrument for prescreening subjects' hypnotizability in the Mandarin Chinese-speaking population in Taiwan.

Hungarian norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A

Hungarian norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) are presented. The Hungarian translation of the HGSHS:A was administered under standard conditions to 434 participants (190 males, 244 females) of several professions. In addition to the traditional self-scoring, hypnotic behavior was also recorded by trained observers. Female participants proved to be more hypnotizable than males and so were psychology students and professionals as compared to nonpsychologists. Hypnotizability varied across different group sizes. The normative data-including means, standard deviations, and indicators of reliability-are comparable with previously published results. The authors conclude that measuring observer-scores increases the ecological validity of the scale. The Hungarian version of the HGSHS:A seems to be a reliable and valid measure of hypnotizability.

Norms of German adolescents for the Harvard Group Scale of Hypnotic Susceptibility, Form A

The Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) has not been explicitly tested on an adolescent population. In this study, the German version of the HGSHS:A was administered to 99 German adolescents aged 15 to 19. In contrast to other studies, the gender distribution was relatively balanced: 57% female and 43% male. Results were comparable to 14 earlier studies with regard to distribution, mean, and standard deviation. Some peculiarities in contrast to the 14 previous studies are pointed out. It is concluded that the HGSHS:A can be used as a valid and reliable instrument to measure hypnotic suggestibility in adolescent samples.

Disseminating hypnosis to health care settings: Applying the RE-AIM framework

Hypnosis is a brief intervention ready for wider dissemination in medical contexts. Overall, hypnosis remains underused despite evidence supporting its beneficial clinical impact. This review will evaluate the evidence supporting hypnosis for dissemination using guidelines formulated by Glasgow and colleagues (1999). Five dissemination dimensions will be considered: Reach, Efficacy, Adoption, Implementation, and Maintenance (RE-AIM).

REACH

In medical settings, hypnosis is capable of helping a diverse range of individuals with a wide variety of problems.

EFFICACY

There is evidence supporting the use of hypnosis for chronic pain, acute pain and emotional distress arising from medical procedures and conditions, cancer treatment-related side-effects and irritable bowel syndrome.

ADOPTION

Although hypnosis is currently not a part of mainstream clinical practices, evidence suggests that patients and healthcare providers are open to trying hypnosis, and may become more so when educated about what hypnosis can do.

IMPLEMENTATION

Hypnosis is a brief intervention capable of being administered effectively by healthcare providers.

MAINTENANCE

Given the low resource needs of hypnosis, opportunities for reimbursement, and the ability of the intervention to potentially help medical settings reduce costs, the intervention has the qualities necessary to be integrated into routine care in a self-sustaining way in medical settings. In sum, hypnosis is a promising candidate for further dissemination.

Portuguese norms for the harvard group scale of hypnotic susceptibility, form a

The Portuguese version of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) was administered to 313 Portuguese college students. Score distribution, item pass rates, item analysis, and reliability of the HGSHS:A are presented and compared to earlier published reference samples. No differences were found between males and females. Reliability of the HGSHS:A Portuguese version was lower than that reported by most of the studies but within the range of the non-English versions. In general, Portuguese data are congruent with the reference samples and the Portuguese translation of the HGSHS:A. It appears to be a viable instrument for primary screening of hypnotic suggestibility in a Portuguese context.

On the objectivity of the scoring of Harvard Group Scale of Hypnotic Susceptibility

The authors analyzed the Harvard Group Scale of Hypnotic Susceptibility, Form A, scores of 1,887 subjects. In addition to the usual self-scoring, trained observers also scored the behavioral manifestations of the subjects according to the same standardized criteria during the sessions. Self- and observer-scoring proved to be internally consistent and highly correlated (r = .832). Item-by-item analysis, however, yielded notable differences. Subjects and observers scored items differently in about 20% of the cases; only 3 items showed no systematic bias toward pass or fail. Many subjects' hypnotizability level would be classified differently according to observer categorization (Cohen's Kappa = .563). We suggest reconsidering the "objectivity" of self-scoring.

The impact of hypnotic suggestibility in clinical care settings

Hypnotic suggestibility has been described as a powerful predictor of outcomes associated with hypnotic interventions. However, there have been no systematic approaches to quantifying this effect across the literature. This meta-analysis evaluates the magnitude of the effect of hypnotic suggestibility on hypnotic outcomes in clinical settings. PsycINFO and PubMed were searched from their inception through July 2009. Thirty-four effects from 10 studies and 283 participants are reported. Results revealed a statistically significant overall effect size in the small to medium range (r = .24; 95% Confidence Interval = -0.28 to 0.75), indicating that greater hypnotic suggestibility led to greater effects of hypnosis interventions. Hypnotic suggestibility accounted for 6% of the variance in outcomes. Smaller sample size studies, use of the SHCS, and pediatric samples tended to result in larger effect sizes. The authors question the usefulness of assessing hypnotic suggestibility in clinical contexts.

Polish norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A

The Polish version of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A; Shor & Orne, 1962) was administered to 1174 participants (968 women and 206 men). Polish data were compared with other norming studies. Point-biserial item-scale correlations ranged from r = .12 (posthypnotic suggestion item) to r = .49. The Kuder-Richardson correlation of .70 was within the range of the reference samples. Test-retest reliability coefficients were obtained from one group of participants tested twice in the same session (r = .69, p < .05), and another group 8 weeks apart (r = .58, p < .05). Females scored significantly higher than males.

Israeli norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A

A Hebrew version of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) was administered to 283 subjects. Results were compared with those obtained for the English original administered in the United States, Canada, and Australia, as well as with versions translated into Swedish, Romanian, Italian, Finnish, Danish, Spanish, and German. Mean scores were similar to the Canadian and Australian, though lower than the others. No differences were found between males and females. Pass rates for individual items were similar or lower than elsewhere. Item reliability was similar to the other non-English versions. The author speculates that the slightly lower scores obtained may be due to the larger group of subjects present in each session. Overall, the Israeli data are congruent with the reference samples.

Language, mysticism, and hypnotizability: a brief communication

People attempting to communicate religious and mystical experiences tend to use the same language strategies employed in inducing hypnotic trance. Both incorporate vague language that provides receptive listeners the opportunity to insert their own content. This study examines whether people who have had mystical or religious experiences are also more likely to respond to the language of hypnosis. Eighty-one participants completed the Harvard Group Scale of Hypnotic Susceptibility, Form A and the Hood Mysticism Scale. Participants were divided into 3 equal groups based on "high," "ambiguous," and "low" mysticism scale scores. The high group scored significantly higher on hypnotizability compared to the low group. The relationship between openness to mystical and religious experience and susceptibility to hypnotic suggestion warrants further investigation.

Italian norms for the Stanford Hypnotic Susceptibility Scale, Form C

This paper presents norms for an Italian translation of the Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C; Weitzenhoffer & Hilgard, 1962). Archival data on hypnosis research subjects recruited over a 10-year period of research on hypnosis were pooled, resulting in an aggregate sample of 356 participants (263 female and 93 male). Score distribution, item difficulty levels, and reliability of the SHSS:C were computed. Of this group, 218 subjects were administered the Harvard Group Scale of Hypnotic Susceptibility approximately 3 weeks prior to administration of the SHSS:C. The remaining 138 subjects received only the SHSS:C. Results suggest that the Italian version of the SHSS:C is a reliable and valid measure.

Italian norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A

Norms for an Italian translation of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) by Shor and Orne (1962) are presented. Subjects recruited from 1986 to 1989 were pooled, resulting in a sample of 376 participants (297 women and 79 men). The normative data were generally congruent with earlier normative studies in score distribution, item difficulty levels, and reliability. Women had significantly higher hypnotizability scores and item pass rates than men. The reliability scores of the Italian adaptation of the HGSHS:A were the same as a previously reported Danish sample and higher than a German sample, but lower than those of the Australian, Canadian, and original American samples. These results suggest that the Italian version of the HGSHS:A is an efficient tool for initial hypnotizability screening in an Italian context.

The Imagination Inventory and its correlates with imagery and hypnotizability

Presented are two studies designed to establish the psychometric properties (Study 1) of the Imagination Inventory (II; Barber and Wilson, 1979), and (Study 2) to examine the relation between subscales derived by factor analysis and measures of hypnotizability: (HGSHS:A; Shor and Orne, 1962), and the Depth of Hypnosis Index (DHI), as well as waking imagination (CIS; Wilson and Barber, 1978). Testing a sample of 459 Polish students, it was found that rationally derived scales developed by Barber and Wilson (1979) failed to parallel the factor structure derived from empirical procedure. The cross-cultural validity of the II was supported by low-to-moderate correlations with the HGSHS:A and the CIS.

Danish norms for the Harvard group scale of hypnotic susceptibility, form A

Norms for a Danish adaptation of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) are presented. Four samples tested from 1988 to 1991 (n = 166, n = 54, n = 95, and n = 61) were pooled, resulting in an aggregate sample of 376 participants. The normative data were generally congruent with earlier normative studies with regard to score distribution, item difficulty levels, and reliability. Studies using the Danish adaptation of the HGSHS:A as a screening instrument have shown the predictive value of the instrument in a Danish context. Data for a comparable American sample of volunteers (n = 170) tested by the same hypnotist were included in the analysis. A comparison revealed a marked difference for the posthypnotic suggestion item, hinting that cultural differences between the Danish and American samples with regard to expectancies and attitudes toward hypnosis may play a role. Further studies comparing attitudes toward hypnosis across different cultural contexts are needed to clarify this issue.

Hypnosis and attention deficits after closed head injury

In a controlled study of patients attending a concussion clinic because of ongoing postconcussion symptoms, attention deficits were recorded in the head-injured group for the aspects of alertness, assessed by the Continuous Performance Test (CPT), and processing capacity, assessed by a version of the Paced Auditory Serial Addition Test (PASAT). Selective attention was intact. Hypnotizability was assessed by the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A), with normal means and standard deviations found in both the concussed and control groups. There was a significant correlation, however, between HGSHS:A scores and PASAT scores in the concussed group only. The results of this preliminary study suggest that slower processing capacity after a closed head injury may predict higher hypnotizability and that hypnosis could be an appropriate rehabilitation technique for these patients who present with postconcussion symptoms.

Spanish norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A

The results of administering the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) of Shor and E. Orne (1962) to a Spanish sample are on the whole consistent with those results obtained in other normative studies, especially Bongartz's work with a German sample, and they confirm HGSHS:A's usefulness in non-Anglophone countries. The Spanish HGSHS:A's reliability and validity remain within the limits reported for other locales, but there are certain discrepancies with respect to the difficulty of two HGSHS:A items.

Effects of hypnosis and level of processing on repeated recall of line drawings

Moderately susceptible subjects (N = 30) initially judged 30 line drawings of objects for pleasantness (deep processing) and 30 line drawings for visual complexity (shallow processing), after which they were given two immediate recall tests. Following a 48-hr delay, subjects were allocated randomly to hypnosis, simulation, or neutral control conditions and were tested four more times. Subjects produced more correct and incorrect responses over the six trials and gave a higher number of correct responses for deep items than for shallow items. Over the last four trials, hypnosis had no general facilitative effect relative to the other two treatments, but the effect of depth was strongest for hypnotized subjects, who recalled more deep items than did the controls. Finally, both hypnotized and simulating subjects rated their recall as more involuntary and their experimental treatment as more helpful than did the controls. Caution is urged in the forensic use of hypnosis as a retrieval device.