Harvard Group Scale of Hypnotic Susceptibility, Form A

Abstract

The Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A), developed by Shor and Orne in 1961, represents a critical adaptation of the widely recognized Stanford Hypnotic Susceptibility Scale, Form A (SHSS:A). While the original SHSS:A required individual administration and objective scoring by a trained examiner (Weitzenhoffer & Hilgard, 1959), the HGSHS:A was designed for efficient group administration utilizing a self-report scoring methodology. This innovation allows the scale to be administered to large groups simultaneously, significantly reducing testing time and resource requirements.

Initial testing conducted on a sample of 132 undergraduates demonstrated that the HGSHS:A yields norms consistent with those established by the original Stanford version. Furthermore, the scale proved effective in predicting subsequent hypnotic depth. The internal consistency of the total scale was evaluated using Kuder-Richardson reliabilities, which were reported as strong, yielding values of .80 and .83 across two distinct samples.

Keywords

Harvard Group Scale of Hypnotic Susceptibility, Form A, HGSHS:A, Hypnosis, Hypnotic Susceptibility, Test Development, Test Reliability, Test Validity, Group Administration, Rating Scale

Authors

Shor, Ronald E., Orne, Emily Carota

Purpose

The primary purpose of the Harvard Group Scale of Hypnotic Susceptibility, Form A, was to create a practical and efficient adaptation of the established Stanford Hypnotic Susceptibility Scale, Form A. This adaptation aimed specifically to facilitate group administration, thereby making research on hypnotic phenomena more accessible and scalable in academic and clinical settings.

By shifting from the resource-intensive individual administration model to a group format with self-report scoring, the authors sought to standardize the measurement of hypnotic responsiveness across large populations without compromising the psychometric integrity or the normative consistency of the original instrument.

Construct

The core psychological construct measured by the HGSHS:A is Hypnotic Susceptibility (or Hypnotizability). This construct refers to the degree to which an individual can respond to hypnotic suggestions, often operationalized by the successful performance of suggested behaviors during a hypnotic induction.

The scale is designed to measure the individual differences in the capacity to experience suggested alterations in perception, sensation, emotion, or memory. It is a fundamental measure used in hypnosis research to categorize subjects based on their responsiveness, which is generally viewed as a stable personality trait.

Validity

The validity of the HGSHS:A is supported primarily through its strong alignment with the established criteria and behaviors measured by the original Stanford scale. Specifically, the scale demonstrates satisfactory Content validity.

The behaviors included in the 12-item measure—such as motor automatisms, challenge catalepsies, amnesia, hallucination, and post-hypnotic suggestion—are components widely accepted within the field as defining the lower to moderate regions of hypnotic depth. The scale’s ability to replicate the normative distribution of the individually administered SHSS:A also lends strong support to its construct validity as a measure of hypnotic responsiveness.

Reliability

The internal consistency reliability of the Harvard Group Scale of Hypnotic Susceptibility, Form A, was evaluated using the Kuder-Richardson Formula 20 (KR-20), a standard method for estimating reliability for instruments scored dichotomously (pass/fail).

The reported Kuder-Richardson reliabilities were robust, measuring .80 and .83 in two separate samples. These values indicate a high degree of homogeneity among the 12 items, suggesting that they are consistently measuring the same underlying construct of hypnotic responsiveness.

Factor Analysis

Based on the available documentation, there is no specific factor analysis indicated or reported for the Harvard Group Scale of Hypnotic Susceptibility, Form A, in the primary source materials. The scale is typically treated as a unidimensional measure of total hypnotic responsiveness.

Instrument

Test Type:

Rating Scale

Format:

Paper-and-pencil, self-report scoring format

Language Available:

English (Original)

Population Group:

Human

Age Group:

Adolescents and Adults (Based on sample population)

Population Details:

The primary validation sample consisted of College Students (undergraduates).

Test Methodology:

The scale is a 12-item measure administered in a group setting. Subjects respond to the suggestions and then score their own performance based on specific criteria provided in the protocol.

Keywords

Hypnotic Depth, Test Construction, Test Reliability, Test Validity, Motor automatisms, Challenge Catalepsies, Amnesia, Hallucination, Post-hypnotic suggestion, Psychometrics, 7200 Personality

Authors

Author ORCID Identifier:

Not Specified

Affiliation Email addresses:

Not Specified

Correspondence Address:

Contact Publisher

Permissions & Fee and Test Year

Permissions:

Permissions must be obtained by contacting the publisher of the original reference (International Journal of Clinical and Experimental Hypnosis).

Fee:

Fee information not specified in the source material.

Test Year:

The primary development and publication year for the HGSHS:A norms was 1961 (Shor & Orne).

Reference’s

• 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

Items of the Harvard Group Scale of Hypnotic Susceptibility – Form A

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

The Harvard Group Scale of Hypnotic Susceptibility – Form A is a 12-item measure. The specific text of the 12 items is not provided in the source content, but the domains measured include:

• Motor automatisms
• Challenge catalepsies
• Amnesia
• Hallucination
• Post-hypnotic suggestion