PSYCHE | J Frank/Corbis/Getty
His ideas about human thinking and behaviour – largely dealing with their imperfections – infiltrated fields from health policy to politics, casino gambling to baseball. His impact was perhaps most dramatic in economics, the discipline for which he won the Nobel Prize in 2002. He often joked about the fact that he had never even taken an economics class. He described his influence on that field, and on every other, as entirely accidental. He was just trying to have fun with his work, and answer some questions about the human mind along the way.