cognitive development

the (natural) growth of human intelligence or mental ability. A key figure in its study is Jean Piaget (1896-1980) who was interested in the change in a person's ability to learn from childhood to adulthood. He developed a theory to account for this process whereby a human acquires intelligence, capacity for increasingly complex thinking, and problem-solving ability, from infancy to adulthood (see abstract, accommodation, assimilation, concrete operational, equilibration, formal operational, preoperational, schema, sensori-motor).