Mental Age and IQ
Originally, the differences between mental age and chronological age were used to compute the intelligence quotient, or IQ. This was computed using the ratio method, with the following formula: mental age/chronological age * 100 = IQ. No matter what the child's chronological age, if the mental age is the same as the chronological age, then the IQ will equal 100.
An IQ of 100 thus indicates a child of average intellectual development. For a gifted child, the mental age is above the chronological age, and the IQ is higher than 140; for an intellectually challenged child, the mental age is below the chronological age, and the IQ is below 70.
Read more about this topic: Mental Age
Famous quotes containing the words mental and/or age:
“For universal love is as special an aspect as carnal love or any of the other kinds: all forms of mental and spiritual activity must be practiced and encouraged equally if the whole affair is to prosper. There is no cutting corners where the life of the soul is concerned....”
—John Ashbery (b. 1927)
“Every age has a keyhole to which its eye is pasted.”
—Mary McCarthy (1912–1989)