Intelligence Tests

Intelligence Tests

Intelligence tests evaluate a person’s cognitive abilities, aiming to measure their capacity for various tasks. As a type of aptitude assessment, intelligence testing focuses on assessing an individual’s potential. These tests typically generate an overall score known as an IQ (intelligence quotient) along with index scores derived from factor analysis. Intelligence tests are commonly employed to identify giftedness, learning disabilities, and intellectual developmental disabilities.

1. Theories of Intelligence

Intelligence is a complex and abstract concept that is challenging to measure and define. It encompasses various abilities such as spatial, verbal, and musical aptitude. There are multiple theories of intelligence, each attempting to provide a definition. Here is a summary of some prominent intelligence theories.

Intelligence Theories

Francis Galton• Developed first intelligence theory.• Emphasized heritability and eugenics.• Theorized that perceptual abilities were critical to the development of intelligence.
Alfred Binet and Theodore Simon• Developed first formal measure of intelligence: the Binet-Simon scale.
Lewis Terman• Revised and translated the Binet-Simon scale and renamed the enhanced version the Stanford-Binet.
William Stern• Developed the ratio intelligence quotient, which is calculated by dividing one’s mental age by chronological age.
Charles Spearman’s twofactor approach• Defined intelligence as a single unit, which he termed “g” (i.e., general factor).• Acknowledged the existence of “s” or specific factors that referred to the skills acquired in a specific area as a result of training.
Louis Thurston’s multifactor• Instead of a “g” factor, Thurston recognized seven primary mental abilities: verbal approach comprehension, word fluency, number ability, spatial ability, associative memory, perceptual speed, and reasoning.
Phillip Vernon’s Hierarchical model of intelligencePostulated that intelligence is made up of factors and skills arranged hierarchically into four levels.
J. P. Guilford’s Multidimensional model• Intelligence is composed of 180 factors and involves three types of cognitive ability: operations, content, and products.His model is shaped as a cube.
Raymond Cattell’s fluid and crystallized intelligence model• Proposed two distinct intelligences: fluid and crystallized.• Fluid intelligence refers to innate ability that is not influenced by experience and education; it consists of reasoning ability, memory capacity, and speed of information processing.• Crystallized intelligence is gained through learning and is greatly affected by life experiences and culture.• Crystallized intelligence will increase with age, whereas fluid intelligence declines as we age.
Robert Sternberg’s triarchic theory of intelligence• Componential (the person’s internal world); experiential (the person’s external world and adaptation to novelty); and contextual (the person’s external world and environmental adaptation or creation).
Howard Gardner’s theory of multiple intelligences• Proposed eight primary intelligences: linguistic, logical-mathematical, musical, spatial, bodily-kinesthetic, intrapersonal, interpersonal, and naturalistic.
Cattell-Horn- Carroll (CHC) theory of cognitive abilities• Recognized as the most empirically validated theoretical model of intelligence.• Proposes that intelligence is hierarchical and consists in three strata: general intelligence “g,” broad cognitive abilities, and narrow cognitive abilities.

2. Intelligence Tests

The intelligence tests are grounded in the theories of intelligence mentioned above. These tests primarily focus on constructs such as “g” and “s” factors, as well as the concepts of crystallized and fluid intelligence. The table provides an overview of today’s commonly used intelligence tests.

Overview of Commonly Administered Intelligence Tests.

Intelligence TestDescription
Stanford-Binet 5• Intended population: persons ages 2 to 90 years.• Format: uses basal and ceiling levels to determine starting and stopping points.• Subtests: measures verbal and nonverbal intelligence across five factors (fluid reasoning, knowledge, quantitative reasoning, visual-spatial processing, and working memory). This creates 10 subtests.• Scoring: uses a mean of 100 and a standard deviation of 15. Raw scores are based on the number of items answered correctly and are converted into a standard score based upon age norms.
Wechsler scalesMost widely used intelligence tests.Has three different tests for various age groups.Scores have a mean of 100 and an SD of 15.
Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV)• Intended population: individuals ages 16 to 89 years.• Subtests: contains 15 subtests (symbol search, coding, cancellation, arithmetic, digit span, letter-number sequencing, matrix reasoning, picture completion, block design, visual puzzles, figure weights, comprehension, similarities, vocabulary, and information).• Scoring: subtests generate a full-scale score and four composite scores (verbal comprehension, perceptual reasoning, processing speed, working memory).
Wechsler Intelligence Scale for Children®—Fifth Edition (WISC-V®)• Intended population: individuals ages 6 to 16 years.• Subtests: contains 10 core subtests (symbol search, coding, digit span, picture span, matrix reasoning, visual puzzles, block design, figure weights, similarities, and vocabulary). In addition to the 10 subtests, there are six supplemental tests (information, comprehension, word reasoning, picture concepts, arithmetic, letter-number sequencing, and cancellation).• Scoring: subtests generate a full-scale IQ score and five primary index scores (verbal comprehension, visual spatial, fluid reasoning, processing speed, and working memory).
Wechsler Preschool and Primary Scales of Intelligence—Fourth Edition (WPPSI-IV™)• Intended population: individuals ages 2 years and 6 months to 7 years and 3 months.• Subtests: composed of 16 subtests (matrix reasoning, vocabulary, picture concepts, bug search, word reasoning, animal coding, comprehension, picture memory, similarities, receptive vocabulary, information, object assembly, block design, picture naming, zoo locations, and cancellation).• Scoring: provides a verbal and performance IQ score and a fullscale IQ score.
Kaufman Assessment Battery for Children (KABC-II)• Purpose: designed to evaluate preschoolers, minority groups, and children with learning disabilities. Provides information about nonverbal intellectual abilities.• Intended population: children ages 3 to 18 years.• Subtests: five subtests (simultaneous, sequential, planning, learning, and knowledge). Has a broad theoretical base that allows the test administrator to use the Luria neuropsychological model and the Cattell/Horn/Carroll (CHC) approach to interpret the subtests.• Scoring: yields four global scores (sequential processing, simultaneous processing, achievement, and mental processing composite). Uses a mean of 100 and a standard deviation of 15.