I.Q.

Intelligence quotient.
This is a measure obtained by tests to assess intellectual ability or intelligence. The IQ is the ratio of mental age to real age multiplied by 100. It is the mental age which is measured in the tests.
Theoretically IQ ranges from 0 to 200. The lower limit of normal is 80, "bright" people have an IQ of over 140 and geniuses have an IQ of over 170.