"Urie Bronfenbrenner (born April 29, 1917, Moscow, Russia, U.S.S.R. — died September 25, 2005, Ithaca, New York, U.S.) was a Russian-born American psychologist best known for having developed human ecology theory (ecological systems theory), in which individuals are seen as maturing not in isolation but within the context of relationships, such as those involving families, friends, schools, neighbourhoods, and society. Bronfenbrenner divided the entire ecological system in which human growth occurs into five subsystems that are organized socially: the microsystem, mesosystem, exosystem, macrosystem, and chronosystem."