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:
“In the new science of the twenty-first century, not physical force but spiritual force will lead the way. Mental and spiritual gifts will be more in demand than gifts of a physical nature. Extrasensory perception will take precedence over sensory perception. And in this sphere woman will again predominate.”
—Elizabeth Gould Davis (b. 1910)
“Hath homely age th’ alluring beauty took
From my poor cheek? Then he hath wasted it.
Are my discourses dull? Barren my wit?
If voluble and sharp discourse be marred,
Unkindness blunts it more than marble hard.”
—William Shakespeare (1564–1616)