Jean Piaget was a Swiss psychologist and philosopher born in 1896 who pioneered the field of developmental psychology. He studied natural sciences and received his PhD in zoology. Piaget identified as a genetic epistemologist concerned with the origin and development of human knowledge. Through his work studying children's intelligence and how they acquire and organize knowledge, Piaget developed the theory that children think differently than adults and progress through distinct stages of cognitive development. Piaget's theories on childhood cognitive development have been highly influential in psychology and education.