Author: Henrik B. Dynesen

A Striking Similarity: The Revolutionary Findings of Twin Studies

“I have looked at the data, and I’m collecting the data, and I’m still absolutely astounded. I still haven’t settled down and absorbed this kind of a finding yet. How long is it going to take me?” These words were uttered by Dr. Thomas J. Bouchard, research director of the Minnesota Study of Twins Reared Apart (MISTRA), during a conversation with the Danish professor of psychiatry, Niels Juel-Nielsen, in May 1981. Bouchard was trying to come to terms with the revolutionary implications of his own research into identical and fraternal twins reared apart. 16 years earlier, Juel-Nielsen had published the book Individual and Environment—a study of 12 Danish identical twin pairs reared apart. Prior to 1981, this was one of only three studies of separated twins: the others were a 1937 American study of 19 twin pairs, and a British study conducted by James Shields in 1962 of 44 twin pairs. An archived recording of their remarkable exchange was rediscovered in 2011 by the twin researcher Dr. Nancy L. Segal. In her 2012 book Born Together—Reared …