David T. Lykken

David Thoreson Lykken (June 18 1928 - September 15 2006) was a behavioral geneticist and Professor Emeritus of Psychology and Psychiatry at the University of Minnesota. He is best known for his work on twin studies.

Life
Born in Minneapolis, Minnesota, at 17, Lykken joined the United States Navy, then attended University of Minnesota on the G.I. Bill, earning his bachelor of arts (psychology, philosophy and mathematics) 1949, his masters degree in psychology and statistics in 1952, and his doctorate in clinical psychology and neuropsychiatry in 1955. He remained on Minnesota’s permanent faculty for his entire career and taught as a visiting professor at Deep Springs College. He was an emeritus professor from1998 until his death.

Work
Lykken was also known for his work on twins, which he began in 1970. He was a principal investigator on the Minnesota Twin Family Study, which examines heritability of certain psychological traits based on evidence found in identical and fraternal twins. He was a signatory of a collective statement in response to The Bell Curve titled "Mainstream Science on Intelligence", written by Intelligence editor Linda Gottfredson and published in the Wall Street Journal in 1994 and in Intelligence in 1997.

Lykken was the proponent of a set-point theory of happiness, which argues that one's sense of well-being is half determined by genetics and half determined by circumstances, and has been the subject of international media attention. His research findings suggest that a person's baseline levels of cheerfulness, contentment, and psychological satisfaction are largely a matter of heredity.

He was elected a Fellow of the American Psychological Association (Division 1), a Charter Fellow of the American Psychological Society and a Fellow of the American Association for the Advancement of Science. He was also a member of the Behavior Genetics Association and the International Society for Twin Research. Throughout his career, he consulted with government and industry. He frequently testified as an expert witness on polygraph testing and personality assessment in the wake of Daubert standard requirements.