Jean Piaget was a Swiss psychologist known for his work on child development and is thought to be a major contributor to developmental psychology. He started off by observing children who used to give wrong answers to logical questions.
According to him, these answers were the differences between the thinking processes between adults and children. Piaget believed that children are born with a very basic mental structure that is genetically inherited and evolved. Everything that is learnt is based here. “Intelligence is an adaptation… To say that intelligence is a particular instance of biological adaptation is thus to suppose that it is essentially an organization and that its function is to structure the universe just as the organism structures its immediate environment” (Piaget, 1963, pp. 3-4). “Intelligence is assimilation to the extent that it incorporates all the given data of experience within its framework…There can be no doubt either, that mental life is also accommodation to the environment.
Assimilation can never be pure because by incorporating new elements into its earlier schemata the intelligence constantly modifies the latter in order to adjust them to new elements” (Piaget, 1963, p. 6-7). Piaget came to believe that intelligence is not something that is, it is a form of adaptation which is constructed through the two processes of assimilation and accommodation. This development in children occurs in four stages.
The sensorimotor stage, preoperational stage, concrete operational stage and the formal operational stage. Each of these processes are built during the early stages of development.