Intelligence is the ability of adjusting to a new situation :
According to Brown: Intelligence is the aggregate or global capacity of the individual to act purposefully, think rationally and deal effectively with his environment.
According to Thomdike : Intelligence is defined as the ability of an individual to cope with his environment. It may be thought of as a composite or organisation of abilitites to learn, to grasp broad and subtle facts, especially abstract facts, with alertness and accuracy to exercise mental control and to display flexibility and ingenuity in seeking the solution for problems.
According to Thomdike, intelligence has three different levels of functioning.
1. Abstract Intelligence : Ability to understand and manage ideas and symbols such as words, numbers, etc.
2. Mechanical Intelligence : The ability to understand and manage man and women and to act wisely in human relations.
3. Social intelligence : The ability to understand and manage men and women and to act wisely in human relations.