Homosexuality in Twins: A Report on Three Discordant Pairs

Abstract

Three homosexuals for anunselected series of twins were briefly described. Two pairs were monozygotic and a third dizygotic. In all 3 the co- twins showed no evidence of any sexual deviation. These observations suggest that factors other than genetic ones may play a significant part in the etiology of homosexuality. In the one adequately documented case, the mother''s attitude, commencing prenatally and continuing in a favorable setting, is considered to be the important factor.