The turning point for the study of childhood development was Jean Piaget, an Italian/Swiss Psychologist, who proposed that both intellectual growth and socialization are driven by cognitive processes in the mind, rather than external influences such as teaching or socialization. His theory of Cognitive Development describes the stages of mental functioning (or age) during childhood and adolescence, and how they relate to the cognitive abilities of children and adolescents. These stages were based on his research into child development and include sensorimotor, preoperational, concrete operational, formal operations, and rational operations. He also developed the notion of assimilation vs accommodation.
Piaget’s observations of children growing into adulthood and learning showed that the prevalent view of children as “miniature adults” was wrong, and led him to believe that their psychological development progresses in recognizable stages. At each stage, the child’s brain functions differently to absorb knowledge from the outside world, building cognitive, emotional, and motor skills. Contrary to the common belief of his day, Piaget believed that these stages were universal across all ages, suggesting that they are natural and genetically determined, not learned.
