Jean Piaget was born in Switzerland in 1896 of a Swiss father (Arthur Piaget) and a French mother (Rebecca Jackson).
At the age of 11, Piaget published a biological paper on molluscs. After high school, he studied zoology obtaining a Ph.D. from the University of Neuchatel in 1918.
In 1918, Piaget also studied psychology under Carl Jung and Paul Eugene Bleuler for a semester, at the University of Zürich. where Piaget developed a deeper interest in psychoanalysis. In 1919, he studied psychology at the Sorbonne in Paris. He married Valentine Chatenay in 1923 and they had 3 children.
Piaget worked initially as a teacher and in his work, observed the cognitive patterns of children. He also observed his own children from the time they were infants. He blended education, natural science and experimental psychology to develop his field of developmental psychology.
From 1925 to 1929 Piaget was professor of psychology, sociology, and the philosophy of science at the University of Neuchâtel. 
In 1929 he became Director of the International Bureau of Education. He maintained this post until 1968, when he retired.
He was a Professor of Developmental Psychology at the Sorbonne in Paris between 1952 and 1963. As an extension of this role, he acted as chief consultant for 2 conferences in the USA in 1964; one at Cornell and the other at UCLA Berkely.
Piaget developed a theory of 4 stages of cognitive development in children:
1) Sensorimotor 2) Preoperational 3) Concrete operational 4) Formal operational
He demonstrated that a child's thinking is not just less mature than an adult's but that children think in quite different ways to adults.
Piaget's undertook very well known studies of children and developed theories and concepts which have had a significant impact on the field of education. He described his work as 'genetic epistemology'. Piaget was awarded a number of honorary degrees as well as the Erasmus prize in 1972 and the Balzan prize in 1978 for his outstanding contributions in social science. Piaget also wrote more than 50 books and authored hundreds of papers in his field.
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