Mental age (MA) - American Education
A level of individual performance on a standardized test, measured in years and months. Often called the intellectual age, MA was introduced by French psychologist Alfred Binet in 1908
, when the Binet-Simon intelligence test was revised. Age norms were established for each level of performance, and any child, regardless of actual chronological age, who scored at any given level of performance was said to have a mental age for that level. Thus, a child of eight or 12 whose score on the Binet-Simon test matched the 10-yearold norm was said to have a mental age of 10. Mental age by itself was found to be an unreliable measure of intelligence, however, because of its dependence on past experiences. Thus, it accelerates during the early years and decelerates in the later years. Because of its unreliability, the concept was replaced with that of the Intelligence Quotient in 1916.