Over the last few decades, the test has been revised and improved. The test is now in its fourth version and is regarded as a reliable assessment of intelligence.
What is the Wechsler IQ Test?
The Wechsler IQ Test is the creation of Romanian-American psychologist David Wechsler. As one of the most influential advocates of the role of non-intellective factors in testing, Wechsler believed that intelligence was made up of several different mental abilities. Wechsler was keen to develop an alternative to the Stanford-Binet Intelligence Scale, devised by Alfred Binet in 1916. He felt that Binet’s test had the following limitations:
It generated a single score as an indicator of overall intelligence It was focused on timed tests It was designed for children, making it an inaccurate test for adults
In the 1930s, Wechsler created the Wechsler-Bellevue Intelligence Scale – an early version of the WAIS test we know today. He produced it during his placement at New York’s Bellevue Psychiatric Hospital. Rejecting the idea that individuals can be defined and measured by an ideal mental age, the Wechsler-Bellevue test became the most widely used adult intelligence assessment in the United States. After later revisions to address weaknesses in Binet’s Intelligence Scale, the Wechsler-Bellevue test became the Wechsler Adult Intelligence Scale. It features the following key differences from the Stanford-Binet Intelligence Scale:
It was created to be used with adults It contains fewer timed tests It provides several different intelligence scores
The test aims to measure adults’ intelligence – defined by Wechsler as “…the global capacity of a person to act purposefully, to think rationally, and to deal effectively with his environment.” Crucially, the test provides candidates with four major scores. These are:
Perceptual reasoning Processing speed Verbal comprehension Working memory
What to Expect From the Wechsler Test
Since its inception in 1955, there have been four different versions of the Wechsler Adult Intelligence Scale. After the initial WAIS came WAIS-R in 1981, and WAIS-III in 1997. The current version – WAIS-IV – was released in 2008. WAIS-IV includes 10 core subtests and five supplemental subtests.
WAIS, 1955
The WAIS was initially created to address the issues in the Wechsler-Bellevue Intelligence Scale, published by Wechsler in 1939. The WBIS battery of tests was composed of subtests included in various other intelligence tests at the time, such as the Binet-Simon scale and Robert Yerkes’ army testing program.
WAIS-R, 1981
The WAIS-R test consisted of six verbal subtests and five performance subtests. The verbal tests were:
Information Comprehension Arithmetic Digit span Similarities Vocabulary
The performance subtests were:
Picture arrangement Picture completion Block design Object assembly Digit symbol
This test provided scores for verbal IQ, performance IQ and full-scale IQ.
WAIS-III, 1997
The third revision of WAIS, this test provided scores for:
Verbal IQ Performance IQ Full-scale IQ
There were also four secondary indices:
Verbal comprehension Working memory Perceptual organization Processing speed
Verbal IQ
The verbal IQ section consisted of seven tests and provided two subindexes of verbal comprehension and working memory. The verbal comprehension index included the following tests:
Information Similarities Vocabulary
The working memory index included:
Arithmetic Digit span
Performance IQ
The performance IQ section included seven tests and also provided two subindexes:
Perceptual organization Processing speed
The perceptual organization index included:
Block design Matrix reasoning Picture completion
The processing speed index included:
Digit symbol-coding Symbol search
WAIS-IV, 2008
WAIS-IV is the current version of the test, released in 2008. It is composed of 10 core subtests and five supplemental subtests, with the 10 core subtests comprising the full-scale IQ. The verbal and performance subscales from previous versions were removed and replaced by the index scores in WAIS-IV. The general ability index (GAI) was included. The 10 core subtests are:
Block design Similarities Digit span Matrix reasoning Vocabulary Arithmetic Symbol search Visual puzzles Information Coding
These are supplemented by the following five subtests:
Letter-number sequencing Figure weights Comprehension Cancellation Picture completion
The current version of the test assesses candidates on the following indexes:
Verbal comprehension Perceptual reasoning Working memory Processing speed
Within these indexes are several tasks that will assess your cognitive ability.
Word descriptions Word definitions General knowledge questions Questions about common components
Perceptual Reasoning
Here you will be tested on concepts such as putting together block puzzles and completing jigsaws. This index will assess your spatial and quantitative reasoning.
Working Memory
To assess your working memory, the test will present you with tasks such as recalling numbers and letters, and answering arithmetic questions.
Processing Speed
Here your processing speed will be assessed through tasks such as transcribing and identifying the presence of symbols.
Test Age Ranges
Wechsler’s test to measure intelligence has evolved further into three separate versions suitable for differing age ranges. The Wechsler Adult Intelligence Scale (WAIS) is used for adults, while the Wechsler Intelligence Scale for Children (WISC) is used for children between the ages of 6 and 16. For children between the ages of 4 and 6.5, there is the Wechsler Preschool and Primary Scale of Intelligence (WPPSI).
How Is the Test Scored?
The above four indexes – Verbal Comprehension Index (VCI), Perceptual Reasoning Index (PRI), Working Memory Index (WMI) and Processing Speed Index (PSI) – each generate a score representing the major components of intelligence. These indexes are also used to generate two broad scores which provide a summary of an individual’s general intellectual abilities. The Wechsler IQ test scores chart is made up of different indexes. The Full-Scale IQ (FSIQ) is based on the total combined performance of the VCI, PRI, WMI and PSI. The General Ability Index (GAI) is based on only the six subtests that comprise the VCI and PRI assessments. Scores for the Wechsler Adult Intelligence Scale range from 0 to 160. An average IQ is considered to be between 90 and 109. A score of 130 or higher allows individuals to consider themselves of superior intelligence.
How to Prepare for the Wechsler IQ Test
If you are taking this intelligence test, there are a few things you can do to prepare and give yourself the best chance of success. First of all, you should find out which version of the test you will be taking. Once you know this, you can take specialist mock tests to practice answering the kinds of questions you will face in the test. You should focus on the main areas that are included in the test – especially the 10 core subtests. Try to memorize multiplication tables so they are easy to recall. You will want to save brain power for quickly calculating equations in your head. Some of the puzzles you will be asked to solve will test your short-term memory. To practice for these, you can take online memory-based exercises and games. Find some interesting puzzles that you enjoy solving, and practice won’t feel like a chore. Also against the clock are speed exercises, where every second counts. Practice these to become familiar with the timer. You can find engaging games online that replicate the tasks in the WPPSI and WISC to help build your child’s skills. When helping your child prepare, try to avoid using terms such as “test prep”, “IQ” or “test practice” in front of them. You should instead use words that they are more familiar with, such as “smart puzzles” or “brain games” as these sound more like fun activities than test revision. Alongside practicing games similar to the tasks in the Wechsler test, there are things you can do to strengthen the capabilities that your child needs to succeed. A wide vocabulary will be beneficial for children taking the test, so set aside time to read to them daily and also let them see you reading for pleasure at home. You could even explore new and unusual words together, making sure you praise them when they use new vocabulary. A good way to help your child learn new words is by asking them open-ended questions. This allows them to choose the right words themselves, improving their understanding of syntax and context. Encourage your child to play games in the playground and at home. If you want to avoid too much screen time, board games are a great alternative. Some of the key skills required for the WISC – such as attention span, anticipation and managing unexpected information – can be strengthened through games. In the lead-up to the test, eat a healthy, balanced diet and take regular exercise. By looking after your body, you are looking after your mind and this will give you the best chance of success. The day before the test, make sure you get a good night’s sleep. When you sleep, all of the knowledge you have revised gets consolidated in your mind, allowing you to recall facts and figures when needed. Know that you have done all you can to prepare for the test, and settle into a peaceful slumber ready to show off your talents. Preparing for a test of any kind can be stressful. Try not to put too much pressure on yourself. In the days before the test, schedule some time to unwind and indulge in your favorite self-care activities to relax your mind. You can find intelligence exercises similar to the Wechsler IQ test online. If you practice these assessments, remember that they are less reliable and are unlikely to generate accurate results. Try to not fixate on your practice scores and simply use the tests as a way to exercise your brain. As the Wechsler Adult Intelligence Scale is a well-known assessment, you are likely to come across it at some point. By following our preparation guidance, you can give yourself the best chance of success.