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ERIC Number: EJ791987
Record Type: Journal
Publication Date: 2008-Apr
Pages: 9
Abstractor: Author
Reference Count: N/A
ISSN: ISSN-1934-9556
The Stability of IQ in People with Low Intellectual Ability: An Analysis of the Literature
Whitaker, Simon
Intellectual and Developmental Disabilities, v46 n2 p120-128 Apr 2008
A meta-analysis of the stability of low IQ (IQ less than 80) was performed on IQ tests that have been commonly used--tests that were derived by D. Wechsler (1949, 1955, 1974, 1981, 1991, 1997) and those based on the Binet scales (L. M. Terman, 1960; L. M. Terman & Merrill, 1972). Weighted-mean stability coefficients of 0.77 and 0.78 were found for Verbal IQ (V IQ) and Performance IQ (P IQ) on the Wechsler tests and 0.82 for Full-Scale IQ (FS IQ) on both Wechsler and Binet tests, for a mean test-retest interval of 2.8 years. Although the majority of FS IQs changed by less than 6 points, 14% changed by 10 points or more. The author suggests that the results of IQ assessment should be treated with more caution than previously thought.
American Association on Intellectual and Developmental Disabilities. P.O. Box 7065, Lawrence, KS 66044-7065. Tel: 785-843-1235; Fax: 785-843-1274; e-mail:; Web site:
Publication Type: Information Analyses; Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Identifiers - Assessments and Surveys: Wechsler Adult Intelligence Scale