Intelligence is a multidimensional construct, defined as the “ability to learn from experience, adapt to new situations, understand and handle abstract concepts, and use knowledge to manipulate one’s environment”. Intelligence is not the same as IQ (Intelligence Quotient), although some people may use these terms interchangeably. IQ is a score derived from a set of standardised tests developed to measure a person’s cognitive abilities in relation to their age.
Current intelligence tests view intelligence not as specific abilities stemming from a general intellectual capacity, but as different types of intelligence, all of an equal importance. Intelligence tests measure an individual’s adaptability to a new environment, their capacity for knowledge, ability to evaluate and judge, their capacity for reason and abstract thought as well as their capacity for original and productive thought.
What is the WAIS and what is it used for?
The Wechsler Adult Intelligence Scale- Fourth Edition (WAIS- IV) is a test designed to measure intelligence in adolescents and adults aged 16 to 90 years. It measures both verbal and performance abilities and can be used for a number of reasons, including:
- Predictors of academic achievement.
- Predictors of work performance.
- Administered as part of a battery of tests to diagnose intellectual disabilities, specific learning disabilities and ADHD.
- Assess how the brain is functioning after an injury. Large differences in verbal and nonverbal intelligence may indicate damage to specific parts of the brain.
- Administered as part of a battery of tests to make inferences about personality and pathology, using both the content of specific answers and patterns of subtest scores.
- Identify distribution of IQ in populations.
Wechsler’s Other Intelligence Scales
After the success of the WBIS, Wechsler went on to develop a range of intelligence scales, including:
- Wechsler Memory Scale (WMS): Published in 1945 the WMS was developed to serve as a clinical test to assess domains of memory including short-term, long-term and working memory. It is also used to detect and evaluate memory disorders.
- Wechsler Intelligence Scale for Children (WISC): Now in its fifth edition, the WISC was originally published in 1949 for use with children aged 6 to 16 years old.
- Wechsler Preschool and Primary Scale of Intelligence (WPPSI): Published in 1967 for the assessment of children between 4 years and 6 years 6 months. The WPPSI is a downward extension of the WISC in which similar, but easier, items are used.
- Wechsler Abbreviated Scale of Intelligence (WASI): Linked to both the WISC and the WAIS this test is for individuals aged 6 to 89 year. The WASI is a quick and reliable estimate of an individual’s level of intellectual functioning. It is also useful for reassessing individuals who have had a comprehensive evaluation.
- Wechsler Nonverbal Scale of Ability (WNV): Published in 2006, the WNV is designed for culturally and linguistically diverse groups aged 4 to 21 years old. It is suitable for individuals whose first language is not English, those who are hearing impaired, gifted individuals from linguistically diverse populations, and individuals with low incidence disorders such as cerebral palsy, aphasia, expressive language disorder or receptive language disorder.
How is the WAIS administered and interpreted?
The WAIS-IV is individually administered by a qualified professional, such as a psychologist who is trained in testing, administration, and interpretation. It is conducted in a well-lit, quiet room that is free from distractions and interruptions. The test is made up of subtests which assesses a person’s verbal comprehension, perceptual reasoning, working memory or processing speed. Administration time varies, with numerous factors including the client’s ability level and/or special needs and test-taking style, the examiner’s administration style and experience and the time required to maintain rapport and/or minimise fatigue. affecting test length.
As noted the test is organised into four index scales: Verbal Comprehension, Perceptual Reasoning, Working Memory and Processing Speed, each producing an individual score. Together, the scales derive the Full Scale IQ. The distribution of IQ scores are arranged along a bell curve with 100 (average score) positioned in the middle of the curve. Scores between above 130 are ‘superior’ 120-129 are ‘very high’, 110-119 are ‘high average’, ’90-109’ are ‘average’, 80-89 are ‘low average’, 70-79 are ‘borderline mental functioning’ and below 70 are ‘extremely low mental functioning’.
In summary, the WAIS has been used for more than 60 years and continues to be one of the most popular and widely used scales for intelligence testing. The WAIS is considered to be a valid and reliable measure of general intelligence and is used by researchers in many areas of psychology as a measure of intelligence. Research has also demonstrated correlations between the WAIS IQ scores and a variety of socioeconomic, physiological and environmental characteristics.
If you are interested in finding out more about intelligence testing, please call 1800 877 924 or book online for an initial consultation.
Camphaus, R. W. (2005). Clinical Assessment of Child and Adolescent Intelligence. (2nd Ed.). Springer Science & Business Media Inc: New York.
Groth-Marna, G. (2003). Handbook of Psychological Assessment. (4th Ed.). John Wiley & Sons, Inc.: New Jersey.
Sternberg, R. J. (2014). Human Intelligence. In Encyclopaedia Britannica online. Retrieved from http://www.britannica.com
Pearson PsychCorp (2008). WAIS-IV Australian and New Zealand Language Adaptation, Administration and Scoring Manual. Sydney: Pearson.
Pearson PsychCorp (2015). Speech and Language. Retrieved from http://www.pearsonclinical.com/language.html