David Wechsler

(1896-1981)

Psychologist

Influences

Education

  • City University of New York, A.B. (1916)
  • Columbia University, M.A. (1917)
  • University of Paris, experimental psychology research (1919-1922)
  • Columbia University, Ph.D. in experimental psychology ( 1925)

Career

  • Army Psychologist assigned to Camp Logan, Texas (1917)
  • Sent by the Army to the University of London to work with C. Spearman and K. Pearson  (1918)
  • Clinical Psychologist at the Bureau of Child Guidance, New York City (1922-1925)
  • Clinical psychology private practice (1925-1932)
  • Chief Psychologist, Bellevue Psychiatric Hospital (1932-1967)
  • Published several assessment instruments, including: Wechsler-Bellevue Scale of Intelligence (1939); Wechsler Memory Scale (WMS) (1945/1997); Wechsler Intelligence Scale for Children (WISC) (1949/2003); Wechsler Adult Intelligence Scale (WAIS) (1955/1997); Wechsler Primary and Preschool Scale of Intelligence (WPPSI) (1967/2002)

Definition of Intelligence

“Intelligence is the aggregate or global capacity of the individual to act purposefully, to think rationally and to deal effectively with his environment (Wechsler, 1944, p. 3).”

Major Contributions

  • Developed several assessments, including two widely-used intelligence scales:
    • Wechsler Intelligence Scale for Children (WISC, 1949; WISC-IV®, 2003)
    • Wechsler Adult Intelligence Scale (WAIS, 1955; WAIS-III®, 1997)
  • Established the use of the deviation IQ, or “DQ” (1939)

Ideas and Interests

David Wechsler is best known for developing several widely-used intelligence tests, including the Wechsler Intelligence Scale for Children (Wechsler, 1949) and the Wechsler Adult Intelligence Scale (Wechsler, 1955). Updated versions of these tests remain popular in the 21st century (WISC-IV®, 2003; WAIS-III®, 1997) and new tests founded on Wechsler’s work continue to be developed by other researchers (e.g. Wechsler & Naglieri, 2006).  Wechsler is also notable for his use of the deviation quotient (DQ), a technical innovation that replaced the use of mental ages in computing IQ scores. This greatly improved the utility of normative comparisons when intelligence tests are used with adult examinees (Edwards, 1994).

When the United States entered the First World War, David Wechsler was finishing up his master’s degree in psychology.  He joined the Army, and this circumstance brought him into contact with several pioneers in the field of intelligence theory, including Karl Pearson, Charles Spearman, Edward Thorndike and Robert Mearns Yerkes. While awaiting his induction Wechsler volunteered to score the Army Alpha test, one of the two group intelligence tests developed by the Committee on the Psychological Examination of Recruits, and it is here that he met Yerkes and Thorndike. Later Wechsler became an individual psychological examiner, and was charged with administering the Stanford-Binet to recruits who had performed poorly on the group intelligence tests (Fancher, 1985).  In 1918 the Army sent him to London to work with Spearman and Pearson.

Wechsler eventually concluded that Spearman’s theory of general intelligence (g) was too narrow.  Unlike Spearman, Wechsler viewed intelligence as an effect rather than a cause, and asserted that non-intellective factors, such as personality, contribute to the development of each person’s intelligence. His personal definition, “Intelligence is the aggregate or global capacity of the individual to act purposefully, to think rationally and to deal effectively with his environment” reflects this broader view (Edwards, 1994; Wechsler, 1940).

The Wechsler Intelligence Scale for Children—Fourth Edition® (WISC-IV®) was published in 2003. It has been normed for use with children aged six through sixteen years and eleven months. It yields a full-scale IQ score and four index scores: Verbal Comprehension (e.g. similarities, vocabulary and comprehension activities), Perceptual Reasoning (e.g. matrix reasoning, block design and picture concepts). Working Memory (e.g. letter-number sequencing and digit-span) and Processing Speed (e.g. symbol search and coding).  The Wechsler Adult Intelligence Scale—3rd Edition (WAIS-III®) was published in 1997, and it can be used with adults between the ages of 16 and 89 years.  Several other Wechsler tests are also available to qualified psychologists:

Wechsler Memory Scale®–Third edition- (WMS—III®)(Wechsler, 1945/1997)

Wechsler Primary and Preschool Scale of Intelligence™ –Third edition (WPPSI™-III) (Wechsler, 1967/2002).

Wechsler Abbreviated Scale of Intelligence (WASI)(Wechsler, 1999)

Wechsler Nonverbal Scale of Ability (WNV) (Naglieri & Wechsler, 2006)

Selected Publications

Wechsler, D. (1939).  The measurement of adult intelligence.  Baltimore:  Williams & Wilkins.

Wechsler, D. (1940).  Non-intellective factors in general intelligence.  Psychological Bulletin, 37, 444-445.

Wechsler, D.(1949). Manual for the Wechsler intelligence Scale for children. New York:  The Psychological Corporation.

Wechsler, D. (1955a).  The Range of human capacities (2nd ed.).  Baltimore:  Williams & Wilkins.

Wechsler, D. (1955b). Manual for the Wechsler Adult Intelligence Scale. New York:  The Psychological Corporation.

Wechsler, D. (1967). Manual for the Wechsler preschool and primary scale of intelligence.  New York:  Psychological Corporation.

References

Edwards, A. J. (1994).  Wechsler, David (1896-1981).  In R. J. Sternberg (Ed.), Encyclopedia of intelligence (Vol. 1, pp. 1134-1136). New York: Macmillan.

Fancher, R. E. (1985). The intelligence men: Makers of the IQ controversy. New York: W. W. Norton & Company.

Wechsler, D. (1940).  Non-intellective factors in general intelligence.  Psychological Bulletin, 37, 444-445.

Wechsler, D. (1944).  The measurement of adult intelligence (3rd ed.).  Baltimore:  Williams & Wilkins.

Wechsler, D. (1945/1997) Wechsler Memory Scale®–Third edition- (WMS—III). San Antonio, TX:  Harcourt Assessment.

Wechsler, D. (1967/2002).  Wechsler Primary and Preschool Scale of Intelligence™ –Third edition (WPPSI™-III).  San Antonio, TX:  Harcourt Assessment.

Wechsler, D. (1997). Wechsler Adult Intelligence Scale—3rd Edition (WAIS-3®) San Antonio, TX:  Harcourt Assessment.

Wechsler, D. (1999).  Wechsler Abbreviated Scale of Intelligence (WASI).  San Antonio, TX:  Harcourt Assessment.

Wechsler, D. (2003).  Wechsler Intelligence Scale for Children—4th Edition (WISC-IV®).  San Antonio, TX: Harcourt Assessment.

Wechsler, D., & Naglieri, J. A. (2006).  Wechsler Nonverbal Scale of Ability (WNV).  San Antonio, TX:  Harcourt Assessment.

Image Courtesy of the National Library of Medicine