Hormones and sexual orientation: a questionable link.

This paper critically reviews the studies which explore a possible causal relationship between sex hormones and the development of sexual orientation. Early studies focused on hormone measurements in adult men and women. While definitive interpretations are hindered by methodological problems, the studies as a whole do not support a causal relationship between postnatal hormone levels and sexual orientation. More recently, a theory that prenatal hormone levels produce varying degrees of brain androgenization and subsequent dimorphic sex role behavior has consistently been supported by studies in lower mammals. Attempts to generalize the causes of sexual orientation from animals to humans have been controversial. Efforts to measure the estrogen feedback as an indication of brain androgenization have produced inconsistent results. Studies of men and women who experienced defect in hormone metabolism (i.e., CAH and testicular feminization) have not found a concurrent increase in homosexual behavior. Overall, the data do not support a causal connection between hormones and human sexual orientation.