Medical Pioneer. One of the preeminent child psychologists of the 20th century, he was born Neuchatel, Switzerland. Known as one of the first leading major figures developmental psychology, Piaget served in many posts including, Research Director at the Institute Jean-Jacques Rousseau, in Geneva, Switzerland, from 1921 to 1925, and 1925 to 1929, Professor of Psychology, Sociology and the Philosophy of Science, at the University of Neuchatel from 1929 to 1939, Professor of the History of Scientific Thought, at the University of Geneva, Switzerland, from 1929 to 1967, Director of the International Bureau of Education, Geneva, Switzerland, from 1932 to 1971, Director of the Institute of Educational Sciences, at the University of Geneva, Switzerland, from 1938 to 1951, Professor of Experimental Psychology and Sociology at the University of Lausanne, Switzerland, from 1939 to 1951, Professor of Sociology at the University of Geneva, Switzerland, from 1940 to 1971, Professor of Experimental Psychology at the University of Geneva, Switzerland, from 1952 to 1964, and Professor of Genetic Psychology at the Sorbonne in Paris, France, in 1955. He also established the Center for Genetic Epistemology, and served there from 1955 until his death in 1980, Director of the International Centre for Genetic Epistemology in Geneva, Switzerland, and also from 1971 until his death in 1980, he was Emeritus Professor at the University of Geneva, Switzerland. Piaget also authored over 95 books and 500 articles on the studies of psychology. Among his writings are, "The Language And Thought Of The Child" (1926), "Judgment And Reasoning Of The Child" (1928), "The Child's Conception Of The World" (1929), "The Moral Judgement Of The Child" (1932), "Child's Conception of Number"(1952), "The Construction Of Reality In The Child" (1954), "The Mechanisms of Perception" (1969), "The Psychology Of The Child" (1969), "The Science of Education And The Psychology Of The Child" (1970), and "Memory And Intelligence" (1973). Piaget died in Geneva, Switzerland in 1980.