Synopsis Psychologists have roughly estimated that there are four levels of intelligence in human beings. It has been estimated on percentage basis. The first 30 per cent individuals have the lowest level of intelligence and are generally termed as imbeciles or idiots. Human being falling in the second category are those whose level of intelligence falls between 30% to 70%. They are termed as people of average intelligence. The third category of human beings falls between 75% to 90% of intelligence and they are called intelligent people. The human beings falling in the category of 90% to 110% are extraordinary caliber people or very intelligent people. This book tries to clarify the concept of intelligence and methods of assessment of intelligence.