Jean Piaget, the psychologist and philosopher, was born in Neuchâtel, Switzerland. He studied zoology at the university there and in 1918 received his doctorate for a thesis on the subject of land mollusks in the Valais Alps. He then studied psychology for a year at Zürich and, from 1919 to 1921, abnormal psychology, logic, and the philosophy of science at the Sorbonne. From 1921 to 1925, he was director of studies at the Institut J.-J. Rousseau (now the Institut des Sciences de l'Éducation) in Geneva; he was its assistant director from 1929 to 1932 and became codirector in 1932. In 1925 he was appointed professor of philosophy at the University of Neuchâtel; in 1929, professor of the history of scientific thought at the University of Geneva; and in 1940, professor of experimental psychology and director of the psychological laboratory at Geneva. He served as professor of child psychology at the...