Jean Piaget was a psychologist who focused on child development. Piaget is arguably most well-known[...]

Jean Piaget, Swiss psychologist who was the first to make a systematic study of the acquisition of understanding in children. He is thought by many to have been the major figure in 20th-century developmental psychology. Learn more about his career and his theory concerning child development.

Jean Piaget created highly influential theories on the stages of mental development among children, becoming a leading figure in the fields of cognitive theory and developmental psychology.

Jean Piaget's Stages of Cognitive Development outlines four stages (sensorimotor, preoperational, concrete operational, formal operational) in a child's cognitive development from infancy to adolescence.

Piaget's Four Stages of Cognitive Development Infographic