Behavioral geneticist who worked on twin studies and lie detection. He was a faculty member at the University go Minnesota for the entirety of his career.
He attended the University of Minnesota where he studied psychology and statistics.
He was a member of the American Psychological Association and he was the proponent of a set-point theory of happiness, which posits that one's sense of well-being is half determined by genetics and half determined by circumstances.
He had three sons with wildlife advocate Harriet Betts Lykken.
He was influenced by Sigmund Freud.