The result, however, showed a mental age of 11½ years, or an I Q of 143.
As it is she is at least a grade below where she belongs by mental age.
Mental age in the first test was 8-6 and in the second test 11.
Their mental age ranges from three to seven years inclusive.
If he goes only as far as normal 8-year-old children ordinarily go, we say that his “mental age” is 8 years.
Thus, an error of 10 months in the mental age of a 5-year-old means an error of almost 15 per cent in the intelligence quotient.
The intelligence quotient (often designated as I Q) is the ratio of mental age to chronological age.
The mental age of a subject is meaningless if considered apart from chronological age.
He is only in the third grade, and is therefore about three grades below his mental age.
This is equivalent to a difference of one year in mental age with 7-year-olds, and to a difference of two years with 14-year-olds.