Most scientists define intelligence as the ability of learn, understand and analyze things, accompanied by a good memory and imagination. This implies that intelligence is a mixture of several abilities. We know that intelligence levels differ form person to person depending upon the aforesaid traits.
Today, neither has the above definition of intelligence been universally accepted nor do the various tests to measure it, have a common appeal. In spite of the difficulties, there is one method widely used to measure intelligence-the intelligence Quotient (IQ) test.
IQ is the abbreviation of psychological phenomenon called intelligence quotient. It is expressed as a number. The IQ of an individual is obtained by dividing his mental age – it is determined by the performance on a standardized intelligence test – by his chronological age, and multiplying the result by 100.
The formal is: IQ = mental age/ real age *100
The mental age of an individual is determined with the help of different tests. Persons are classified under different categories depending on their IQ scores. The following table shows a generally accepted classification of different categories of people in relation to their IQ scores.
Classification table
IQ range category
140 or above genius
Gifted
Very intelligent
70 to 140 bright averages
Average intelligence
Below 69 to 139 mentally retarded
At one time, many psychologists believed that everyone had some degree of inborn intelligence. It was also believed that intelligence was a natural trait like blue eyes, sharp nose, etc., and could be ascertained in a single test. But a French psychologist, Alfred Binet, exploded this myth. He developed a test that helped distinguish between intelligent and dull children. His first tests were tried on some French school children in 1905. Later in 1915, a German psychologist William Stern and a US psychologist Lewis Terman adopted these tests.
Many psychologists believe that these intelligence tests are not the rue indicators of one’s intelligence level and do not give a complete picture of the factors that make up intelligence. For example, some tests measure what one has learnt but not how quickly one has learnt. We know that the grasping power among different people is different. They differ in their ability to understand and remember ideas. They also differ in the use of their knowledge and earlier experiences to solve problems. Hence, till today there is no fully accepted definition of intelligence.
It has been, however, concluded that intelligence mainly depends on heredity and the environment. Every person is born with certain mental abilities. The development of that ability may be activated or slowed down by his or her background. The socialization process, which includes the environment, plays an important role in shaping one’s intelligence. A child becomes a quick learner in areas which he experiences and observers in his day-to-day life. A child who is constantly ridiculed or beaten up may develop a complex due to which he may not be able to develop his intellectual abilities fully. Many children who face discrimination because of race or physical defects fail to develop their mental abilities. Form these facts; it is clear hat intelligence is not a natural trait like blue eyes. There is not a single trait that can be called intelligence, nor any single factor which determines it.