Jean Piaget

He married Valerie Chatenay in 1923. The couple had three children whom he studied from infancy and used this research as the foundation of his work on studying cognitive development in children.

He died in 1980 at the age of 84.

He was born as the eldest son of Arthur Piaget, a professor of medieval literature and Rebecca Jackson. His father was Swiss while his mother was French.

He developed a deep interest in biology and natural sciences as a child and had already published several articles on mollusks by the age of 15.

He received education in natural sciences and philosophy before becoming a psychologist.

He received his doctorate from the University of Neuchatel in 1918 and then undertook post doctoral training at the University of Zurich from 1918 to 1919.

He moved to France after completing his studies. He found employment at the Grange-Aux-Belles Street School for Boys which was run by Alfred Binet, the developer of Binet’s intelligence tests.

Piaget noticed a marked difference in the way younger children gave wrong answers to certain questions as opposed to older children. This led him to conclude that young children’s cognitive processes are different from older children and adults.

He returned to Switzerland in 1921 to work as director of research at the Rousseau Institute in Geneva. At that time Edouard Claparede was the director of the Institute and Piaget was familiar with his ideas on psychoanalysis.

During the 1920s, he became increasingly interested in the psychology of young children. He explained that children moved from a position of egocentrism to sociocentrism with the help of a semiclinical interview.

He served as the professor of psychology, sociology, and philosophy of science at the University of Neuchatel from 1925 to 1929.

He was one of the most influential development psychologists of the 20th century who was best known for propounding the theory of cognitive development. He influenced the works of future generations of eminent psychologists studying not just human behaviour, but also the behaviour of non-human species like primates.