Intelligence is a general ability that enables an individual to learn from experience, form judgements, handle concepts and modify behavior. Intelligence can be nurtured by education and upbringing, the use of intelligence will be determined by individual motivation and drive.

Intelligence is multifactorial- a general level of ability subsumes certain special abilities e.g. verbal, numerical, spatial, logical, memory and tests of intelligence are designed to test these separate areas. Intelligence increases with age until 16, accompanied by brain growth and education. Intelligence slowly declines after 40 - a decreased ability to learn new things.