David Wechsler
Encyclopedia
David "Wex" Wechsler was a leading American
psychologist
. He developed well-known intelligence scales, such as the Wechsler Adult Intelligence Scale
(WAIS) and the Wechsler Intelligence Scale for Children
(WISC).
family in Lespezi
, Romania
, and immigrated with his parents to the United States
as a child. He studied at the City College of New York
and Columbia University
, where he earned his master's degree in 1917 and his Ph.D. in 1925 under the direction of Robert S. Woodworth
. During World War I
he worked with the United States Army
to develop psychological tests to screen new draftees while studying under Charles Spearman
and Karl Pearson
.
After short stints at various locations (including five years in private practice), Wechsler became chief psychologist
at Bellevue Psychiatric Hospital
in 1932, where he stayed until 1967. He died in 1981, his psychological tests already being highly respected.
(WAIS) was developed first in 1939 and then called the Wechsler-Bellevue Intelligence Test. From these he derived the Wechsler Intelligence Scale for Children
(WISC) in 1949 and the Wechsler Preschool and Primary Scale of Intelligence
(WPPSI) in 1967. Wechsler originally created these tests to find out more about his patients at the Bellevue clinic and he found the then-current Binet IQ test
unsatisfactory. The tests are still based on his philosophy that intelligence is "the global capacity to act purposefully, to think rationally, and to deal effectively with [one's] environment" (cited in Kaplan & Saccuzzo, p. 256).
The Wechsler scales introduced many novel concepts and breakthroughs to the intelligence testing movement. First, he did away with the quotient scores of older intelligence tests (the Q in "I.Q.
"). Instead, he assigned an arbitrary value of 100 to the mean intelligence and added or subtracted another 15 points for each standard deviation
above or below the mean the subject was. Rejecting a concept of global intelligence (as was propagated by Charles Spearman
), he divided the concept of intelligence into two main areas: verbal and performance (non-verbal) areas, each further subdivided and tested with a different subtest. These conceptualizations are still reflected in the most recent versions of the Wechsler scales.
The WAIS is today the most commonly administered psychological test (Kaplan & Sacuzzo, 2005). The tests are currently updated approximately every ten years to compensate for the Flynn effect
.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
psychologist
Psychologist
Psychologist is a professional or academic title used by individuals who are either:* Clinical professionals who work with patients in a variety of therapeutic contexts .* Scientists conducting psychological research or teaching psychology in a college...
. He developed well-known intelligence scales, such as the Wechsler Adult Intelligence Scale
Wechsler Adult Intelligence Scale
The Wechsler Adult Intelligence Scale intelligence quotient tests are the primary clinical instruments used to measure adult and adolescent intelligence. The original WAIS was published in February 1955 by David Wechsler, as a revision of the Wechsler-Bellevue Intelligence Scale...
(WAIS) and the Wechsler Intelligence Scale for Children
Wechsler Intelligence Scale for Children
The Wechsler Intelligence Scale for Children , developed by Dr. David Wechsler, is an individually administered intelligence test for children between the ages of 6 and 16 inclusive that can be completed without reading or writing...
(WISC).
Biography
Wechsler was born in a JewishHistory of the Jews in Romania
The history of Jews in Romania concerns the Jews of Romania and of Romanian origins, from their first mention on what is nowadays Romanian territory....
family in Lespezi
Lespezi
Lespezi is a commune in Iaşi County, Romania. It is composed of six villages: Buda, Bursuc-Deal, Bursuc-Vale, Dumbrava, Heci and Lespezi.-References:...
, Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...
, and immigrated with his parents to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
as a child. He studied at the City College of New York
City College of New York
The City College of the City University of New York is a senior college of the City University of New York , in New York City. It is also the oldest of the City University's twenty-three institutions of higher learning...
and Columbia University
Columbia University
Columbia University in the City of New York is a private, Ivy League university in Manhattan, New York City. Columbia is the oldest institution of higher learning in the state of New York, the fifth oldest in the United States, and one of the country's nine Colonial Colleges founded before the...
, where he earned his master's degree in 1917 and his Ph.D. in 1925 under the direction of Robert S. Woodworth
Robert S. Woodworth
Robert Sessions Woodworth was an influential American academic psychologist of the first half of the twentieth century. A graduate of Harvard and Columbia, his textbook Psychology: A study of mental life, which appeared first in 1921, went through many editions and was the first introduction to...
. During World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
he worked with the United States Army
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
to develop psychological tests to screen new draftees while studying under Charles Spearman
Charles Spearman
Charles Edward Spearman, FRS was an English psychologist known for work in statistics, as a pioneer of factor analysis, and for Spearman's rank correlation coefficient...
and Karl Pearson
Karl Pearson
Karl Pearson FRS was an influential English mathematician who has been credited for establishing the disciplineof mathematical statistics....
.
After short stints at various locations (including five years in private practice), Wechsler became chief psychologist
Psychologist
Psychologist is a professional or academic title used by individuals who are either:* Clinical professionals who work with patients in a variety of therapeutic contexts .* Scientists conducting psychological research or teaching psychology in a college...
at Bellevue Psychiatric Hospital
Bellevue Hospital Center
Bellevue Hospital Center, most often referred to as "Bellevue", was founded on March 31, 1736 and is the oldest public hospital in the United States. Located on First Avenue in the Kips Bay neighborhood of Manhattan, New York City, Bellevue is famous from many literary, film and television...
in 1932, where he stayed until 1967. He died in 1981, his psychological tests already being highly respected.
Intelligence scales
David Wechsler is best known for his intelligence tests. The Wechsler Adult Intelligence ScaleWechsler Adult Intelligence Scale
The Wechsler Adult Intelligence Scale intelligence quotient tests are the primary clinical instruments used to measure adult and adolescent intelligence. The original WAIS was published in February 1955 by David Wechsler, as a revision of the Wechsler-Bellevue Intelligence Scale...
(WAIS) was developed first in 1939 and then called the Wechsler-Bellevue Intelligence Test. From these he derived the Wechsler Intelligence Scale for Children
Wechsler Intelligence Scale for Children
The Wechsler Intelligence Scale for Children , developed by Dr. David Wechsler, is an individually administered intelligence test for children between the ages of 6 and 16 inclusive that can be completed without reading or writing...
(WISC) in 1949 and the Wechsler Preschool and Primary Scale of Intelligence
Wechsler Preschool and Primary Scale of Intelligence
The Wechsler Preschool and Primary Scale of Intelligence is an intelligence test designed for children ages 2 years 6 months to 7 years 3 months developed by David Wechsler in 1967. It is a descendent of the earlier Wechsler Adult Intelligence Scale and the Wechsler Intelligence Scale for Children...
(WPPSI) in 1967. Wechsler originally created these tests to find out more about his patients at the Bellevue clinic and he found the then-current Binet IQ test
Stanford-Binet IQ test
The development of the Stanford–Binet Intelligence Scales initiated the modern field of intelligence testing and was one of the first examples of an adaptive test. The test originated in France, then was revised in the United States...
unsatisfactory. The tests are still based on his philosophy that intelligence is "the global capacity to act purposefully, to think rationally, and to deal effectively with [one's] environment" (cited in Kaplan & Saccuzzo, p. 256).
The Wechsler scales introduced many novel concepts and breakthroughs to the intelligence testing movement. First, he did away with the quotient scores of older intelligence tests (the Q in "I.Q.
Intelligence quotient
An intelligence quotient, or IQ, is a score derived from one of several different standardized tests designed to assess intelligence. When modern IQ tests are constructed, the mean score within an age group is set to 100 and the standard deviation to 15...
"). Instead, he assigned an arbitrary value of 100 to the mean intelligence and added or subtracted another 15 points for each standard deviation
Standard deviation
Standard deviation is a widely used measure of variability or diversity used in statistics and probability theory. It shows how much variation or "dispersion" there is from the average...
above or below the mean the subject was. Rejecting a concept of global intelligence (as was propagated by Charles Spearman
Spearman's hypothesis
Spearman's hypothesis states that the magnitude of the black-white difference in tests of cognitive ability is entirely or mainly a function of the extent to which a test measures general mental ability, or g...
), he divided the concept of intelligence into two main areas: verbal and performance (non-verbal) areas, each further subdivided and tested with a different subtest. These conceptualizations are still reflected in the most recent versions of the Wechsler scales.
The WAIS is today the most commonly administered psychological test (Kaplan & Sacuzzo, 2005). The tests are currently updated approximately every ten years to compensate for the Flynn effect
Flynn effect
The Flynn effect is the name given to a substantial and long-sustained increase in intelligence test scores measured in many parts of the world. When intelligence quotient tests are initially standardized using a sample of test-takers, by convention the average of the test results is set to 100...
.