Over the years, several intelligence tests have been developed, and the Wechsler Adult Intelligence Scale (WAIS) evaluation test is one of them. This test has become a standard to test intelligence in adults and much older adolescents.

What is WAIS: A Quick History

This test was first published by David Wechsler, the psychologist, in 1955. According to him, intelligence is not mutually exclusive but influenced by a set of mental abilities as opposed to a single factor.

He was not satisfied with the limitations of the popular Stanford Binet test of the time because he believed that the test had its limitations. The Standford Binet intelligence test focused on a single test score for times tasks. Secondly, it was focused on children making it an inappropriate rest for adults.

These were his complaints against the Standford Binet test so he devised a new test called the Wechsler-Bellevue Intelligence Scales. It was later upgraded to Wechsler Adult Intelligence Scale (WAIS).

How Does It Work?

Today, there are four versions of the test, which are:

  • WAIS – 1955
  • WAIS-R – 1981
  • WAIS-III – 1997
  • WAIS-IV – 2008

The 2008 version is the most recent one and is widely used today. It includes 10 core subjects and 5 supplementary subjects, and 4 major test scores in the following areas:

  • Perceptual Reasoning
  • Processing Speed
  • Scores Provided
  • Verbal Comprehension
  • Working Memory

The current version of 2008 works with two overall summary scores, which are the General Ability Index and the Full-Scale IQ. These summary scores made it a standard for intelligence tests about 30 years after it was developed for adults because they addressed the weaknesses of the Stanford Binet test.

The WAIS has become the most popular intelligence test for older adolescents and adults.

WAIS-IV is an improvement of the WAIS-R and WAIS-III versions. The WAISR was published in the 80s with 6 verbal and 5 tests. The tests were:

  • Comprehension
  • Vocabulary
  • Similarities
  • Digit Span
  • Arithmetic
  • Information

The performance tests were:

  • Picture Completion
  • Picture Arrangement
  • Object Assembly
  • Block Design
  • Digit Symbol

From these subjects, performance and verbal IQ were evaluated.


Before the current WAIS-IV of 2008 was WAIS-III, which was released later on in 1997. This test evaluated Performance IQ, Scale IQ, and Verbal IQ and was an upgrade of WAIS-R. There were 4 tests which were:

  • Verbal Comprehension
  • Processing Speed
  • Perceptual Organization
  • Working Memory

The verbal IQ has 7 tests and 2 subindexes for working memory and verbal comprehension. The latter tested similarities, vocabulary, and information, while the memory function tested for Arithmetic and digital span.

The Use Of WAIS-IV

WAIS-IV is used to measure intelligence in people between the ages of 16-90 years. For younger people below 16 years, the Wechsler Preschool & Primary Scale of Intelligence is used instead for 2 ½ – 7 years, while the Wechsler Intelligence Scale for Children is used for children of 6-16 years.

Intelligence tests are mainly used to assess the cognitive functions in individuals or for psychiatric evaluation of illnesses or brain injuries. Psychologists and neuropsychologists use the test to assess a patient’s brain function after an injury. Furthermore, specific subtests provide insight into particular cognitive functions and other attention difficulties.

The WAIS-IV can also be used to evaluate intellectual giftedness in individuals, which is why it is highly used in high IQ societies and groups like the:

• Triple 9 Society

• Mensa

• Intertel

The Second Edition

After WAIS-IV of 2008, there was a second edition called the Wechsler Abbreviated Scale of Intelligence. This short test was developed by Pearson in 2011. It was designed to evaluate the intellectual function in individuals within a shorter period as opposed to WAIS-IV, which covered a longer period. Unlike WAIS-IV, WAIS-III only had 4 subjects, namely:

  • Block Design
  • Matrix Reasoning
  • Vocabulary
  • Similarities

These were fewer than the 10 core subjects covered by WAIS-IV. Although the 4 subjects had the same structure as WAIS-IV, the questions were different.

WAIS-III derives its overall scores from a combination of 4 subtests including the Verbal Comprehension Index derived from Vocabulary & Similarities Subtest raw scores.

Standardization of WAIS: Test Score

WAIS-IV became a standard after it was used to test about 2200 candidates in the US between the ages of 16-90 years. The test was expanded to include 688 Canadians within the same bracket. The full median IQ score was 100, with 15 as the accepted standard deviation. Based on the normal score distribution, anyone with an IQ range above one standard deviation and below the standard mean will score between 85-115.

This score represents the average score of 68% of the adult population. Any score above 115 is rated as high intellect.

For more than 30 years now, WAIS has been the standard intelligence score for adults, and recent improvements have increased the validity of its scores. From the look of things, more upgrades will most likely be introduced to make it more efficient in evaluating the intellect of adults in the coming years.