Multiple predictors of hypnotic susceptibility.

In this article, we report two experiments in which various measures thought to be related to hypnotizability were analyzed by stepwise discriminant analysis techniques. Absorption (Tellegen, 1981, 1982; Tellegen & Atkinson, 1974) and preference for an imagic style of thinking (Isaacs, 1982) were robust predictors of hypnotizability; each variable accounted for significant variance in hypnotizability at their respective steps in two samples and correctly classified a significant proportion of low- and high-hypnotizable subjects in the discriminant analyses. The addition of two other variables in Experiment 2—a Sleep–Dream score derived from Evans's (1977) Cognitive Control of Sleep Mentation subscale and Gibson's (1985) Dream Questionnaire, and the Belief in the Supernatural subscale of the Taft (1969) Experience Questionnaire—increased the correct classification of the medium-hypnotizable subjects from chance levels to 74%. It is argued that a confirmatory and hierarchical approach is needed in future studies to explore correlates of hypnotizability more fully. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The heritability of hypnotic susceptibility in twins.

Tested 140 pairs of twins (mean age = 9 yrs) and their families on the Stanford Hypnotic Susceptibility Scale, Form A. A significant heritability index for the scores of the twin pairs and a significant correlation between the midparent score (i.e., the average of the mother's and father's score) and the mean child score were obtained, supporting a genetic component in hypnotizability. However, a statistically significant interaction between parent hypnotizability and the child's hypnotizability, conditional upon the resemblance of the child to the like-sexed parent in personality, was interpreted as a consequence of environmental influence, either through social learning or identification. (25 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correlates of hypnotic susceptibility.

An attempt was made to relate hypnotic susceptibility to the following: an inventory of subjective nonhypnotic personal experiences, attitudes and opinions toward and interest in hypnosis, environmental and social perceptions, 5 Guilford-Martin personality scales, and measures of response styles. The Harvard Group Scale of Hypnotic Susceptibility was administered to 80 male and 97 female college students who had previously taken the questionnaires. The results and conclusions were generally negative. Judging from the present results and those in previous studies, hypnotic susceptibility is not closely related to available personality inventories or measures of "social and environmental perceptions" and probably not to measures of subjective nonhypnotic personal experiences. An S's previous hypnotic experience, attitude toward hypnosis, and expectations regarding his own hypnotizability do appear to influence his susceptibility. (40 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cortical event-related potentials show the structure of hypnotic suggestions is crucial

Electroencephalographic cortical event-related potentials (ERPs) are affected by information processing strategies and are particularly appropriate for the examination of hypnotic alterations in perception. The effects of positive obstructive and negative obliterating instructions on visual and auditory P300 ERPs were tested. Twenty participants, stringently selected for hypnotizability, were requested to perform identical tasks during waking and alert hypnotic conditions. High hypnotizables showed greater ERP amplitudes while experiencing negative hallucinations and lower ERP amplitudes while experiencing positive obstructive hallucinations, in contrast to low hypnotizables and their own waking imagination-only conditions. The data show that when participants are carefully selected for hypnotizability and responses are time locked to events, rather robust physiological markers of hypnosis emerge. These reflect alterations in consciousness that correspond to participants' subjective experiences of perceptual alteration. Accounting for suggestion type reveals remarkable consistency of findings among dozens of researchers.     

Developmental expression of perlecan during murine embryogenesis

Participants (N = 206) experienced 15-min of monotonous drumming either before or after hypnosis (Harvard scale). Participants completed the Phenomenology of Consciousness Inventory (PCI) in reference to the last 4-min of drumming. Stimulus order did not affect the objective trance levels as measured by the Harvard scores. The subjective trance level as measured by hypnoidal scores (predicted Harvard scores from the PCI) was significantly higher when drumming preceded hypnosis. Participants' estimated average trance level achieved during drumming fell in the medium range of susceptibility (5-8) (Pekala, 1995). Participants who achieved higher hypnoidal and Harvard scores were more likely to report relaxed feelings and shamanic-type experiences in narratives about their subjective experiences during drumming.     

Nonshared environmental influences and personality differences in adult twins.

The twin design was used to examine the importance of different experiences of siblings within the family and to identify relations between twins' personality differences and their differential experiences. A sample of 161 monozygotic and 74 dizygotic twin individuals between the ages of 18 and 75 years retrospectively reported on their different experiences when growing up. The Sibling Inventory of Differential Experience (SIDE) was used for the first time with a sample of twin siblings. In addition, the twins provided self-report measures of affect and personality. In contrast to results from a sibling adoption design, this study of twins showed greater evidence for genetic variance in the SIDE scales. Nevertheless, the SIDE showed significant associations with differences in personality and affect for monozygotic twins, which reflect pure environment–behavior relations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response expectancies and interpretations as determinants of hypnotic responding.

Ss rated the extent to which they expected to respond to each of the suggestions on a hypnotizability scale both before and after the administration of the preliminary hypnotic induction procedure. After the induction, Ss also rated the extent to which they planned to respond actively and passively to each suggestion. Contrary to strong versions of response-expectancy theory, the extent to which Ss planned to adopt an active interpretation predicted behavioral and subjective indexes of hypnotizability even after controlling for the effects of postinduction expectations. In addition, an active interpretation significantly predicted response to suggestion for which Ss held weak and uncertain expectations. The relationship between expectation and hypnotizability was found to be fan-shaped rather than linear. Implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnotizability and the deployment of waking attention.

Although most theoretical accounts of hypnosis stress the contribution of attentional processes, such processes have not been considered extensively in past efforts to identify correlates of hypnotizability. A recently developed measure of waking attention deployment—the random-number generation task (RNG)—is described, and the relation between RNG scores and hypnotizability is presented. In 5 heterogeneous subgroups, 68 college-age Ss performed a 2-min RNG task and were administered the Harvard Group Scale of Hypnotic Susceptibility, Form A. 41 of these Ss later received the individually administered Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C). Highly susceptible Ss (score of 8+ on each scale) demonstrated significantly better RNG performance than less susceptible Ss. This finding was replicated when using the SHSS:C as the measure of hypnotizability. Good randomizers scored an average of 2–3 points higher on both hypnotizability scales than poor randomizers. It is suggested that the process of deautomatization may be the common attentional mechanism that underlies hypnotizability and that is reflected in differential RNG performance. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of life event stress on physical illness: Substantive effects or methodological flaws?

Tested the hypothesis that the reported relationship between life event stress and physical illness is primarily a function of criterion and other content contamination in the stress measure. In particular, conventional life event measures included events related to physical health, which overlap with the criterion; events related to neuroticism, which influences the criterion; and vague or subjective events that could be affected by individual differences in psychological distress, response sets, and retrospective bias. 386 adult males and females (who ranged in age from their early 20's to their 90's) completed a version of the Schedule of Recent Experience, the Seriousness of Illness Rating Scale, the Neuroticism-Extraversion-Openness Inventory, and the Eysenck Personality Inventory. Illness was significantly related to event subscales containing, respectively, health-related events, neuroticism-related events, and subjective events, but not to an "uncontaminated" event subscale. These results support the hypothesis of contamination and suggest that alternative approaches to the conceptualization and measurement of stress may need to be developed. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development and application of a measure of students' college experiences.

Describes the College Experience Inventory (CEI), developed by the authors to assess student experiences during college. The CEI was administered to 743 university seniors at the end of their college careers. Analyses of the Ss' responses resulted in 12 CEI factors that were found to be significantly related to life-history data collected 4 yrs prior to the administration of the CEI. Subgroups of Ss based on life history were meaningfully differentiated by the CEI. Longitudinal patterns of experiences (paths) followed by Ss through their 4 yrs of college could be identified. Ss who selected one path to the exclusion of others were found to differ on selected academic criteria. Results indicate that the CEI has potential for use in student counseling and university placement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the degree of stability of measured hypnotizability over a 25-year period.

Conducted a longitudinal study of hypnotizability, as measured by the Stanford Hypnotic Susceptibility Scale, Form A, that yielded a relatively high degree of stability in hypnotic responsiveness over repeated testings spanning a 25-year period. The 50 Ss were retested in 1985, after tests when they were students, between 1958–1962 and again in 1970. The statistically significant stability coefficients were .64 (10-year retest), .82 (15-year retest), and .71 (25-year retest). The means did not change significantly, and the median change in the scores of individuals was only 1 point on the 12-item scale. A set of score measures and their intercorrelations are insufficient to resolve the issue of why stability occurs. The stability of hypnotizability over time compares favorably with that of other measures of individual differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Situational Appraisal Inventory: Development and validation of a measure of evaluative attitudes.

Designed the Situational Appraisal Inventory (SAI) to meet the need for a measure of subjective moral (evaluative) attitudes. Previous instruments used were found inadequate because of their psychometric properties or psychological assumptions. 2 100-item forms (SAI-A and SAI-B) were developed and standardized for college populations and a 30-item form (SAI-J) was derived from SAI-A to represent the cluster dimensions and total score of the longer form. Internal consistency and test-retest reliabilities of all forms exceeded .90 and all forms of the test were shown to be comparable. SAI scores related as expected to measures of parental identification and religiosity, and were consistently higher for females than for males. SAI scores did not relate to measures of social desirability response set. The SAI was considered to be a reliable and valid measure of subjective evaluative attitudes. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time distortion and hypnotic ability: Underestimating the duration of hypnosis.

In a replication of previous research, 3 different samples of Ss (109 Ss) underestimated the length of time they were hypnotized. However, as in a previous investigation, there was no significant relation between Ss' hypnotizability and the amount of temporal foreshortening of the hypnotic interval. A small subset of Ss (13–23%) in each of 3 separate samples overestimated instead of underestimated the length of time they had been hypnotized. When this small group of overestimators is set aside, the correlations between hypnotic ability and temporal estimates become significant for each of the 3 (sub)samples of underestimators—ranging from –.41 to –.53. It is demonstrated that these correlations could not be accounted for by R. F. Ornstein's (1969) storage-size hypothesis, but were probably due to Ss of varying hypnotizability becoming differentially absorbed in the hypnotic proceedings. This understanding is consistent with work in time perception showing that imaginative absorption leads to a foreshortening of time. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Susceptibility of the trauma symptom inventory to malingering

This study examined the sensitivity and specificity of the Trauma Symptom Inventory (TSI; Briere, 1995), a self-report measure of psychological sequelae of potentially traumatic events, to malingering. An optimal cutting score for a validity scale--Atypical Responding (ATR)--designed to identify exaggeration or other unusual response sets was developed in an analogue sample of 155 college students and subsequently applied to TSI profiles from several samples of patients with various psychiatric disorders. Use of a cross-validated T-score cutoff of 61 and below on the ATR scale produced good sensitivity (81%) and specificity (92%) rates in the analogue sample. Participants in the analogue sample who reported a history of traumatic experiences were no more able to successfully malinger trauma symptoms than were participants without such histories. Furthermore, false-positive rates in the clinical samples were generally low, suggesting that relatively few genuinely symptomatic individuals would be misclassified as malingering.     

Surreptitiously observed hypnotic responding in simulators and in skill-trained and untrained high hypnotizables.

Low-hypnotizable Ss (LHs) administered cognitive skill training exhibited substantially higher posttest hypnotizability than LHs administered no treatment. Next, the Ss in these 2 conditions as well as Ss who attained high hypnotizability without training and LHs instructed to fake hypnosis (i.e., simulators) were individually tested for hypnotizability twice while their responses were recorded by a hidden camera. In the individual session, Ss were first tested for hypnotizability while alone and then tested again in the presence of an experimenter. The skill-trained Ss and high-hypnotizable controls attained equivalent (high) hypnotizability scores with the experimenter both absent and present. However, when the experimenter was absent, the simulators exhibited lowered hypnotizability and apparently failed to adopt the hypnotic role. These findings contradict the hypothesis that high hypnotizability in skill-trained Ss reflects compliant responding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential experience of siblings in the same family.

The Sibling Inventory of Differential Experience (SIDE), developed by the authors, was completed by 396 12–28 yr old White siblings from both adoptive and nonadoptive homes. The SIDE asks each individual to compare his/her experiences to those of one of his/her siblings in the domains of sibling interaction, parental treatment, peer characteristics, and events specific to the individual. Results indicate that, on the average, siblings experienced quite different environments, especially in the areas of differential sibling interaction and differential peer characteristics. Differential sibling experience as assessed by the SIDE showed little genetic influence, which implies that its origin is primarily environmental. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Reals", "roles", and demand features: A critical look at interview versus questionnaire measures of subjective states.

Hypothesized that questionnaire self-report measures of altered state experience are, by their very nature, affected by demand features, while interview self-report measures of subjective experience are more resistant to these vulnerabilities. It was hypothesized that an interview measure would distinguish the experiences of actual meditators (reals) from their role-playing counterparts (roles), while a questionnaire measure, the Phenomenology of Consciousness Inventory (PCI), would fail to so distinguish. It was also hypothesized that the order in which Ss were to complete the subjective measures would influence their PCI intensity scores, but not the content of their interviews. Data from 51 female undergraduates (aged 18–56 yrs) indicate that these hypotheses were generally confirmed. Findings support the greater validity of more "subjective" interview methods in research on qualitative states. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Longitudinal effects of adolescent girls' pubertal development, perceptions of pubertal timing, and parental relations on eating problems.

This study examines how young adolescent girls' pubertal development and perceptions of pubertal timing as well as their subjective experiences with their parents relate to the emergence of eating problems during later adolescence. The sample consisted of 240 White girls from 2 suburban communities near a large midwestern city. They were studied originally when they were in the 5th to 9th grades and again 2 years later (N?=?177). They reported their daily experiences according to the Experience Sampling Method. Results indicate that adolescent girls' positive relationships with both parents relate to healthier eating scores, both concurrently and longitudinally. Interactions of the pubertal and the experience with parents variables appear to be important for understanding eating problems in early adolescence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personality and the experience of time.

Conducted 2 studies to investigate the effects of personality, as dichotomized along a thought-action dimension, on time perception. Study 1 divided 27 10-48 yr old psychiatric patients into groups depending on whether their weighted color responses on the Rorschach exceeded or were exceeded by the sum of the movement responses. Ss with an introversive Experience Balance (EB) overestimated time, whereas Ss with an extratensive EB underestimated time. Study 2 used 24 normal undergraduates divided into high introversive and high extraversive based on the Maudsley Personality Inventory. 2 time judgments were obtained from each S, and the effect of situational factors (stress) as well as personality was noted. Results are similar to those of Study 1. The time estimation of the action-oriented Ss was significantly more influenced by situational factors than were the time judgments of the ideational Ss. The relationship between thought-action and time estimation was significant in both normal and clinical samples. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fantasy proneness: Hypnosis, developmental antecedents, and psychopathology.

In 7 studies, 6,000 college students were screened to obtain 5 samples of 156 fantasy-prone Ss. Fantasy-prone Ss were selected from the upper 2–4% on a measure of imaginative involvement and were contrasted with nonfantasizers (lower 2–4%) and medium fantasy-prone Ss. Wilson and Barber's construct of fantasy proneness was supported. Fantasizers differed from nonfantasizers on measures of hypnotizability, imagination, waking suggestibility, hallucinatory ability, creativity, psychopathology, and childhood experiences. Differences in hypnotizability were most reliable when Ss participated in a multisession study and were screened not only with the screening inventory, but also with an interview that substantiated their fantasy-prone status. However, our findings indicated that less correspondence between fantasy proneness and hypnotizability exist than Wilson and Barber suggested. Hypnotic responsiveness is possible even in the absence of well-developed imaginative abilities, and not all fantasizers were highly hypnotizable. Fantasizers recollected being physically abused and punished to a greater degree than other Ss did and reported experiencing greater loneliness and isolation as children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)