intelligence quotient

American  

noun

Psychology.

1. an intelligence test score that is obtained by dividing mental age, which reflects the age-graded level of performance as derived from population norms, by chronological age and multiplying by 100: a score of 100 thus indicates a performance at exactly the normal level for that age group. IQ

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intelligence quotient British  

noun

1.  IQ.  a measure of the intelligence of an individual derived from results obtained from specially designed tests. The quotient is traditionally derived by dividing an individual's mental age by his chronological age and multiplying the result by 100

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intelligence quotient Cultural  

1. A number meant to measure intelligence. Once the standard measure of human mental capacity; now widely considered to be neither accurate nor fair. Controversy exists today over the effect of race and class on scores and whether IQ tests really measure intelligence. Tests of special aptitudes and personality factors are now favored over the pure intelligence test.

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The IQ was originally calculated using the ratio of a person's “mental age” (as measured by a standardized test) and chronological age. An IQ between 90 and 110 is considered average; over 120, superior. (See Stanford-Binet scale.) Few tests still include the controversial notion of mental age.

Etymology

Origin of intelligence quotient

First recorded in 1920–25

Example Sentences

To be sure, it is not the first time he has mocked individuals’ intelligence quotient.

From The Guardian • Aug. 10, 2018

The most widely known measure of intelligence is the intelligence quotient, more commonly known as the IQ test, which includes visuospatial puzzles, math problems, pattern recognition, vocabulary questions, and visual searches. 

From Scientific American • Oct. 3, 2017

They do so because they have forgotten to develop their emotional quotient with the same devotion they applied to developing their intelligence quotient.

From New York Times • Jun. 14, 2014

Buffalo Bills quarterback Ryan Fitzpatrick sports the scruffy beard of an outdoorsman, the size and strength of some running backs and the intelligence quotient of your average nuclear physicist.

From Washington Post • Oct. 26, 2011

The intelligence quotient of this girl is 140, which is not reached by more than one child in two hundred.

From The Measurement of Intelligence An Explanation of and a Complete Guide for the Use of the Stanford Revision and Extension of the Binet-Simon Intelligence Scale by Cubberley, Ellwood Patterson