Who Studied The Kallikak Family?

Who Studied The Kallikak Family? American psychologist Henry Herbert Goddard published the book The Kallikak Family: A Study in the Heredity of Feeble-Mindedness in 1912. This book was highly influential in the eugenics movement, and used provocative photographs to further its theses. The Kallikak Family is an example of family study. Who conducted the study