Intelligence is the highest attribute of human beings. Different psychologists have defined intelligence differently. Lewis Terman explains intelligence as, “an ability to think on an abstract level.

David Wechsler defines intelligence as, “the aggregate or global capacity of an individual to act purposefully, to think rationally and to deal effectively with his environment.

On the basis of material used in the tests, intelligence tests can be classified as Verbal tests and Non-verbal tests of intelligence. Intelligence tests that use language (words or numbers) for measuring intelligence are called verbal tests of intelligence. In these tests

subjects are required to respond verbally to test items. Army Alpha Test, Wechsler’s Adult Intelligence Scale (WAIS), etc., are some of the examples of verbal tests of intelligence. These tests are language and culture bound and hence cannot be used with children, illiterates etc. However, they are useful in measuring higher mental abilities.