The Wechsler Adult Intelligence Scale

The Wechsler Adult Intelligence Scale (WAIS) is an intelligence test first published in 1955 and designed to measure intelligence in adults and older adolescents. The test was designed by psychologist David Wechsler, who believed that intelligence was made up of a number of different mental abilities rather than a single general intelligence factor.

History

Wechsler was dissatisfied with what he believed were the limitations of the Stanford-Binet intelligence test. Among his chief complaints about that test was the single score that emerged, its emphasis on timed tasks, and the fact that the test had been designed specifically for children and was therefore invalid for adults.

As a result, Wechsler devised a new test during the 1930s, known as the Wechsler-Bellevue Intelligence Scales. The test was later revised and became known as the Wechsler Adult Intelligence Scale, or WAIS.

WAIS vs. Stanford Binet

One interesting thing to note is that Alfred Binet, the developer of the world's first intelligence test, also believed that intelligence was far too complex a subject to be sufficiently described by a single number.

The goal of his original test was to help identify children who needed specialized help in school and he felt that a variety of individual factors, including a child's level of motivation, could influence test scores.

In a sense, Wechsler's test was a return to many of the ideas that Binet had also espoused. Instead of giving a single overall score, the WAIS provides a profile of the test-taker's overall strengths and weaknesses.

One benefit of this approach is that the pattern of scores can also provide useful information. For example, scoring high in certain areas but low in others might indicate the presence of a specific learning disability.

Like the traditional Stanford-Binet test, the WAIS also provides an overall score. However, Wechsler utilized a different approach to calculating this number. As you might remember from reading about the history of intelligence testing, scores on the early Stanford-Binet were derived from dividing mental age by chronological age.

On the WAIS, Wechsler instead compared scores of the test-taker to those of others in his or her general age group. The average score is fixed at 100, with approximately two-thirds of all scores falling somewhere between 85 and 115.

Test scores that fall between these two numbers are considered average, normal intelligence. Many other intelligence tests later decided to adopt Wechsler's method, including the modern version of the Stanford-Binet.

Versions of the WAIS

There have been four different versions of the WAIS over the years. These include:

• WAIS (1955)
• WAIS-R (1981)
• WAIS-III (1997)
• WAIS-IV (2008)

Current Version

The current version of the WAIS was released in 2008 and includes ten core subtests as well as five supplemental subtests. Additionally, the WAIS-IV test provides four major scores.

The WAIS-IV also provides two overall summary scores including a Full-Scale IQ and a General Ability Index. The WAIS surpassed the Stanford-Binet in use during the 1960s. Today, the WAIS is the most frequently intelligence test in the world with both adolescents and adults. Data collection for the newest version of the test (WAIS-V) is progressing through spring 2020.

A Word From Verywell

Although there are many different reasons why the WAIS might be used, it's sometimes used by neuropsychologists and rehabilitation psychologists in people who have been injured. They are able to utilize the test to see what areas of the brain have been affected as well as determine cognitive function.