IQ, or intelligence quotient, is commonly used as a measure of an individual’s level of intelligence. Right from early childhood an individual’s level of intelligence grows with age. A normal child of a certain age is taken to have a certain level of intelligence which can be measured by a set of carefully designed tests, such as identifying objects, answering simple objective tests and solving simple arithmetical or logic problems. If the performance of the child matches with that expected from an average child of the same age; that is, if his age in years is the same as his mental age, the , child has an IQ of 100. If the performance is below average, it is less than 100, and if above average it is more than 100. The IQ is calculated by dividing the mental age by the actual age in years and multiplying the ratio by 100.
