Encyclopedia of Child Behavior and Development

2011 Edition
| Editors: Sam Goldstein, Jack A. Naglieri

Intelligence Quotient

  • Marie C. McGrath
Reference work entry
DOI: https://doi.org/10.1007/978-0-387-79061-9_1519



A score representing overall level of performance on psychological tests of intelligence or cognitive ability.


Intelligence quotients (more commonly referred to as IQ scores) provide quantitative information on an individual’s overall performance on measures of cognitive ability. Early intelligence tests quantified cognitive ability in the form of “mental quotient” scores, which were calculated by dividing an individual’s “mental age” (MA), or the age group in which the typical individual demonstrated the same level of ability as the test-taker, by that individual’s chronological age (CA). In 1916, test developer and intelligence researcher Lewis Terman adapted this calculation method by multiplying the MA/CA ratio by 100 to yield an integer rather than a decimal; he referred to the resulting scores as an “intelligence quotient.” In Terman’s schema, typical performance for one’s age was represented by...

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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Marie C. McGrath
    • 1
  1. 1.Department of Graduate PsychologyImmaculata UniversityImmaculataUSA