Intelligence is the highest attribute of human beings. Different psychologists have defined intelligence differently.

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.’

The two main perspectives on intelligence are-

(i) Intelligence as a single, general ability – The classical notion of intelligence explains it as an unitary ability and only the functions of intelligence may take different forms.

Psychologists like Alfred Binet, David Wechsler, William Stern and Lewis Terman believed that intelligence is a single index of cognitive abilities.

(ii) Intelligence as a set of multiple abilities – The modern view of intelligence as explained by psychologists like Charles Spearman, E.L. Thorndike, Howard Gardner, etc., states that multiple abilities are involved in intelligence.

Howard Gardner in his theory of multiple intelligence asserted that there are nine independent types of intelligence that grow and develop differently in different people, depending upon the individuals heredity characteristics or environmental experiences.

These nine types of intelligences are-

1. Linguistic intelligence 

2. Logical-mathematical intelligence 

3. Spatial intelligence 

4. Musical intelligence 

5. Bodily-kinesthetic intelligence 

6. Interpersonal intelligence and 

7. Intra-personal intelligence 

8. Naturalistic intelligence and 

9. Existential intelligence