Much of his work focuses on reifying sex differences, with a sociobiological take on things like rape and sexual orientation.
Ellis grew up on a farm near Iola, Kansas. He attended Pittsburg State University in Pittsburg, Kansas, earning a B.A. in Sociology in 1966 and an M.S. in Sociology in 1970. He then attended Florida State University, graduating with a Criminology Ph.D. in 1983, minoring in Psychology.