Piaget, Jean /zhän pē·äzhā″/ [1896–1980] , a Swiss psychologist and genetic epistemologist who established the Genevan school of developmental psychology. From his original training in zoology and his early work in testing schoolchildren in the laboratory, Piaget developed a premise that human intelligence is an extension of biological adaptation. He assumed that human intelligence evolves in a series of stages that are related to age. At each successive stage, intellectual adaptation is more general and shows a higher level of logical organization.
