Homosexuality in families of boys with early effeminate behavior: an epidemiological study.

In the course of a long-term study of 55 boys with early effeminate (cross-gender) behavior an effort was also made to ascertain the presence of sexual deviance in their parents, siblings, uncles, and aunts. For most of these groups of relatives, only one to three members in each group were found to be homosexual, equaling 4% male and 1% female for the total test population. Compared to similar studies, the results were not too different except in the case of the siblings of one study where the incidence was much higher. Some evidence is considered for the speculation of a nongenetic, congenital cause of homosexuality.