Intelligence
Quotient (IQ)

Intelligence quotient (IQ) is derived using standardised psychometric testing. This is a quantitative and objective approach in viewing the mental ability of an individual, in terms of cut-off points on intelligence tests.

Intelligence quotient (IQ) is derived using standardised psychometric testing. This is a quantitative and objective approach in viewing the mental ability of an individual, in terms of cut-off points on intelligence tests.

The following is a rough breakdown of various IQ score ranges. However, bear in mind that it is crucial to remember that IQ tests are only one measure of intelligence. Studies have included other important elements that contribute to intelligence, (e.g., social and emotional factors).

There are many intelligence tests available today including online tests. To get a close to accurate gauge on one’s IQ score, a standardised test must be used. Standardised assessments are formal assessments that have been designed to measure a child’s abilities compared to other children of her/his age group. These tests have been normed on thousands of children, of varying abilities to determine the average level of ability. Your child’s score can then be matched to the average score for other children in that age group.

The most commonly used standardised IQ tests are the Wechsler Scales and The Stanford-Binet. The Wechsler tests are the most common individually administered intelligence tests. They currently include the WISC-V (revised & updated version of the WISC-IV; age 6-16 years), the WAIS-IV (age 16-89 years), and the WPPSI-III (age 2.5 – 7 years). The Stanford-Binet was the first test to use the concept of intelligence. It is now in its 5th edition and reports intelligence as four scores: Verbal Reasoning, Abstract/Visual, Quantitative, and Short-term Memory.

Most intelligence tests consist of subtests measuring various qualities, such as factual knowledge, short-term memory, abstract reasoning, visual-spatial abilities, and common sense. Intelligence is always measured relative to a particular culture. Therefore it is hard to imagine a test being culture-free. Although these tests do a good job of predicting academic success, they do not measure interpersonal skill or creativity.

The Wechsler Intelligence Scale for Children®

Fourth Edition (WISC IV)

 

This scale identifies key cognitive strengths and weaknesses related to learning disabilities, executive function, attention disorders, intellectual disability, and giftedness. Administered between 65 and 80 minutes, the WISC-IV contains 10 core subtests and 5 additional subtests. These are summed to four indexes (the Verbal Comprehension Index, the Perceptual Reasoning Index, the Working Memory Index and the Processing Speed Index) and one Full-Scale IQ (FSIQ) which ranges from lowest 40 to highest 160 points. Subtests are given for additional examination of processing abilities. The age range for this test is between 6 years and 16 years 11 months.

 

Four main indexes of the WISC-IV and what they measure:

Verbal Comprehension Index (VCI)

Measure: Verbal concept formation.

It assesses children’s ability to listen to a question, draw upon learned information from both formal and informal education, reason through an answer, and express their thoughts aloud. It can tap preferences for verbal information, a difficulty with novel and unexpected situations, or a desire for more time to process information rather than decide “on the spot.”
Note: This index is a good predictor of readiness for school and achievement orientation, but can be influenced by background, education, and cultural opportunities.

Perceptual Reasoning Index (PRI)

Measure: Non-verbal and fluid reasoning.

It assesses children’s ability to examine a problem, draw upon visual-motor and visual-spatial skills, organize their thoughts, create solutions, and then test them. It can also tap preferences for visual information, comfort with novel and unexpected situations, or a preference to a learn by doing.

Working Memory Index (WMI)

Measure: Working memory.

It assesses children’s ability to memorize new information, hold it in short-term memory, concentrate, and manipulate that information to produce some result or reasoning processes. It is important in higher-order thinking, learning, and achievement. It can tap concentration, planning ability, cognitive flexibility, and sequencing skill, but is sensitive to anxiety too. It is an important component of learning and achievement, and ability to self-monitor.

Processing Speed Index (PSI)

Measure: Processing speed.

It assesses children’s abilities to focus attention and quickly scan, discriminate between, and sequentially order visual information. It requires persistence and planning ability, but is sensitive to motivation, difficulty working under a time pressure, and motor coordination too. Cultural factors seem to have little impact on it. It is related to reading performance and development too. It is related to Working Memory in that increased processing speed can decrease the load placed on working memory, while decreased processing speed can impair the effectiveness of working memory.

The Wechsler Intelligence Scale for Children®

Fifth Edition WISC V (Latest Version)

 

The WISC V is an individually administered comprehensive clinical instrument for assessing the cognitive ability/intelligence of children aged 6 years 0 months through 16 years 11 months (6:0 – 16:11). This test is the latest version of the most proven trusted cognitive ability measure available with more flexibility and more content. It has been redesigned to give a truly comprehensive picture of a child’s abilities and it includes notable improvements to make identifying the issues and finding the solutions. The WISC–V gives you flexibility and interpretive power, along with access to more subtests, so you get a broader view of a child’s cognitive abilities. New subtests are targeted to common referral questions for children such as the presence of a specific learning disability. An expanded factor structure provides new and separate visual-spatial and fluid reasoning composites for all ages.

Administration of the 10 primary subtests is recommended for a comprehensive description of intellectual ability. The 6 secondary subtests can be administered in addition to the primary subtests to provide a broader sampling of intellectual functioning and to yield more information for clinical decision-making.

The following scores are provided:

  • A Composite Score (from seven of the 10 primary subsets) that represents a child’s overall intellectual ability (FSIQ)
  • Five Primary Index Scores that measure the following areas of cognitive functioning: Verbal Comprehension Index (VCI), Visual-Spatial Index (VSI), Fluid Reasoning Index (FRI), Working Memory Index (WMI), and the Processing Speed Index (PSI).
  • Three (of five) Ancillary Index Scores are also provided: The Quantitative Reasoning Index (QRI); Auditory Working Memory Index (AWMI); Nonverbal Index (NVI); General Ability Index (GAI); and the Cognitive Proficiency Index (CPI).

New Primary Subtests

Three new primary subtests extend the content coverage of the WISC-V and increase its practical application.

  • Visual Puzzle is a new Visual Spatial subtest that measures the ability to analyze and synthesize information
  • Figure Weights is a new Fluid Reasoning subtest that measures quantitative reasoning and induction
  • Picture Span is a new Working Memory subtest that measures visual working memory

 

New Complementary Subtests

Five new complementary subtests have been added to assess cognitive processes important to academic achievement in reading, math and writing, and have shown sensitivity to specific learning disabilities and other clinical conditions. These subtests include a measure of naming facility (Naming Speed and Naming Quantity) and visual-verbal associative memory (Immediate, Delayed and Recognition Symbol Translation).

 

Expanded and Updated Factor Structure

The test structure includes new and separate visual-spatial and fluid reasoning composites for greater interpretive clarity and a variety of levels of composites for interpretive options.


Primary Index Scales include:

  • Verbal Comprehension Index (VCI)
  • Visual-Spatial Index (VSI)
  • Working Memory Index (WMI)
  • Fluid Reasoning Index (FRI)
  • Processing Speed Index (PSI)


Ancillary Index Scales include:

  • Quantitative Reasoning Index (QRI)
  • Auditory Working Memory Index (AWMI)
  • Nonverbal Index (NVI)
  • General Ability Index (GAI)
  • Cognitive Proficiency Index (CPI)


Expanded Index Scores

  • Verbal(Expanded Crystallized) Index(VECI)
  • Expanded Fluid Index(EFI)


Complementary Index Scales include:

  • Naming Speed Index (NSI)
  • Symbol Translation Index (STI)
  • Storage and Retrieval Index (SRI)


Use of WISC V

The WISC–V can be used for diverse applications such as:

  • identifying intellectual disabilities,
  • identifying and diagnosing learning disabilities/disorders,
  • evaluating of cognitive processing strengths and weaknesses,
  • assessing for giftedness and assessing the impact of brain injuries