The present scale is the fourth edition, known as the WAIS-IV.
Psychologist David Wechsler(1896-1981) created what we now refer to as the Wechsler IQ test. He developed the first Wechsler Bellevue Scale in 1939 and some 15 years later revised it into the WAIS.
As an aside, David Wechsler’s study of memory loss before the First World War provided a foundation for his curiosity about intelligence and how it is tested.
Wechsler eventually became interested in children’s IQ scores. He considered the effect of environment on intelligence and decided that a person’s IQ is open to influences.
As well, Wechsler observed that qualities such as persistence can affect general intelligence. He designed intelligence tests that could be applied to a range of ages.
You can read a full and informative biography about David Wechsler and his work with intelligence testing here.
If you take the Wechsler intelligence test, you can expect to receive a full-scale IQ score (which represents general intelligence), a verbal IQ score and a performance IQ score. You would be scored on intelligence in verbal and analytic reasoning.
What To Expect In The Wechsler IQ Test
There are 11 separate subtests in the Wechsler IQ test (the verbal scale is six subtests and the performance scale is five subtests). You would receive scaled scores on the subtests, as well.
The types of Wechsler intelligence tests include the Wechsler Pre-School and Primary Scale of Intelligence (WPPSI) for ages three to seven years; the Wechsler Intelligence Scale for Children (WISC) for ages seven to 16; and the Wechsler Adult Intelligence Scale (WAIS) for ages 16 and above.
The Verbal WAIS scales include questions about information (measuring general knowledge), digit span, vocabulary, math, comprehension and similarities. The performance WAIS scales include tests of picture completion, picture arrangement, block design, and digit symbol and object assembly.
The Wechsler IQ test and the scale have been adapted in various countries and there have been attempts to make the scale more culturally fair. You can learn more about the Wechsler IQ test history and the story of David Wechsler here.
The most recent version of the Wechsler test, version number 4, was released in 2008.
Close to 70 per cent of the population would fall within one standard deviation of the test scale, putting them at an IQ test score of between 85 and 115.
You can learn more about the IQ test scale here.
Want to learn more? There’s a full overview of the history of IQ testing here.
You can also read about a variety of other IQ tests on your classic IQ tests page.
Info on another popular IQ test alternative, the Stanford Binet, is available too.