deviation IQ

Show Summary Details

Quick Reference

The modern, statistical conception of IQ, introduced in 1939 by the Romanian-born US psychologist David Wechsler (1896–1981), according to which IQ is a normally distributed variable with a mean of 100 and a standard deviation of 15 (usually). By definition, an IQ of 100 is average, approximately 68 per cent of IQ scores fall between 85 and 115, approximately 95 per cent fall between 70 and 130, approximately 99.74 fall between 55 and 145, and so on. See also normal distribution. Compare ratio IQ. [So called because it is based on standard deviations]

Subjects: Psychology.

Reference entries

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.