A Swiss child psychologist and epistemologist. Jean Piaget attained his doctorate from the University of Neuchatel in 1918, with a dissertation on the categorization of mollusks. He then dug into psychology and philosophy at the Universities of Zurich and Paris prior to taking up employment at the Jean-Jacques Rousseau Institute of Geneva, a facility for research on child development. Piaget is most widely recognized for his theoretical work and research on mental development.