Measurement of Intelligence
One of the oldest and most useful of the tests of behavior is that which is intended to measure and predict the intellectual capacity of man. The test of intelligence hold a very practical origin in selecting grade school children who would profit from different training. Intelligence tests are useful for assessing differences among adults. The intelligence test has been analyzed for its contribution to the understanding of various performance differences among the men.
From the beginning of intelligence testing there have been two parallel trends, one towards performance tests and other towards verbal test-tests in which the instructions are given in words and in which a good deal of the performance is in the farm of words. Performance tests can be given to people who do not know the language or who have not been to school. They are often blind. People with poor vision and hearing or to children whose handicap seem more severe in verbal than in other areas.
Binet Test of General Intelligence:
He noted that the intellectual capacity increase with age, the intelligent person would be less susceptible to distraction, more like to adopt the situation to achieve a goal and likely to criticize his own work.
If you give a child same test twice with enough time between two tests, you will find that his scores would improve as he grew older. He would certainly do better at the age of 18th than at the age of 4 years. However, a time would come when his ability to answer the test questions would no longer improve. A person does not stop learning even he reaches to mental maturity. Generally mental maturity reached some where between 14 to 18th age. The generally accepted figure is 15th year.
It is a degree of intelligence exhibited by an individual in relation to other of his age group. Binet and Simson have development a scale called as mental age scale for measuring brightness and dullness among the individuals.
Binet testing of school children classified individuals into levels of mental development, which is called as mental age. (M.A.) Binet and Simson scale was applied as follows- A child who passes all the eight year old test is regarded as 8 year old mentally, however his actual age (chronological age) may be 6 year. So he is mentally 2 years in advance. Another child with mental age of 8 may be 11 years old means in this case he is retarded in three years. So brightness or dullness in terms of number of years, advance of retardation.
Intelligence Quotient (I.Q.):
William Sterm says that you can get a number that would show how intelligent a person. This is by dividing his mental age by his chronological age. The I.Q. is obtained by dividing mental age by chronological age and multiplying by 100. Formula of I.Q. is
Intelligent Quotient = ———————————– x 100
= ———————————- x 100
The concept of mental maturity raises an interesting problem. Ex. Think of 15 years old with a mental age of 15. Clearly, his I.Q. is 100 or his mental age is still presumable 15 year. Therefore his I.Q. sunk from 100 to 75 I.Q. we must take the denominator age as 15. For avoiding these difficulties Wechsler-Bellevue adult Intelligence scale is used. Here final score is not calculated from mental age values of the tests passed by the person being examine, but from the total number of points made by him on all tests.