intelligence quotient

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

intelligence quotient

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

intelligence quotient

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.

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.

Word History and Origins

Origin of intelligence quotient¹

First recorded in 1920–25