What is intelligence?

Intelligence is characterized by a mental process that incorporates speed, efficiency, agility and flexibility in the purposeful mental activity of dealing with life tasks, problem solving and the production of both conventional and innovative ideas, services and products.

Intelligence has been defined differently in different epochs, Definitions have ranged from Diogenes’s (300 AD) description o0f Pythagoras’s none-too-helpful description of intelligence as ‘winds’ to Descartes’s definition that intelligence is the ability to judge true from false.

Albert Einstein (1879-1955)

The most often definition is Wechsler’s statement that ‘intelligent is the aggregate or global capacity of the individual to act purposefully, to think rationally and to deal effectively with his environment’.

While definition of intelligence proposed by American Psychological Association in 1995 was that intelligence is the ability ‘to understand complex ideas, to adapt effectively to the environment, to learn, from experience, to engage in various forms of reasoning, to overcome obstacles by taking thought.’
What is intelligence?