Jean Piaget was born. Renowned throughout the world for his pioneering theories of child development and learning, Piaget is widely considered one of the twentieth century's most influential psychologists. Drawing on genetic epistemology to explore the growth of knowledge within the cognitive world of the child, Piaget introduced a number of seminal concepts within the field of developmental psychology, including mental structures, assimilation, accommodation and equilibration.

Acclaimed throughout his career, Piaget collected honorary doctorates from Harvard, The Sorbonne and Cambridge University and received the American Psychological Association (APA) Award for Distinguished Scientific Contributions in 1969.