Jean Piaget

Jean Piaget was a Swiss psychologist who spent decades studying how children develop understanding from infancy forward. He called his approach genetic epistemology - tracing the origins of knowledge itself. In 1934, as Director of the International Bureau of Education, he warned that only education could prevent societal collapse. Two decades later, in 1955, he founded the International Center for Genetic Epistemology in Geneva while teaching at the University of Geneva, directing it until his death in 1980. The center's productivity earned it the nickname "Piaget's factory" in academic circles. His constructivist theory - the idea that learners actively build knowledge rather than passively receive it - spread through the 1960s and turned developmental psychology into a major field. By century's end, only B. F. Skinner had been cited more.