Understanding intelligence: An eco-evolutionary perspective.

In spite of its perceived importance the nature of intelligence remains scientifically poorly understood and the subject of many disagreements both biologically and psychologically. In particular, its key processes and the nature of its variation are obscure, and differences between human and other species remain theoretically unbridged. In consequence there is no unifying principle to explain the origins and evolution of intelligence. The main problem, it is suggested here, is an inadequate grasp of what, in its origins and evolution, intelligence is for - due, in turn, to an over-simple, idealized, view of the environmental challenges intelligence evolved to meet. Here, a description of real environmental complexity is advanced, on the basis of which it is argued that, far from making a late appearance, intelligence was the very basis of the origins of life. How intelligent systems became a common principle in the evolution of living things, is then illustrated, from single cell metabolism to human socio-cognition. The unifying perspective may help to gain for intelligence the scientific status it deserves.