Psychoendocrine Research on Sexual Orientation. Current Status and Future Options

Abstract

This chapter discusses the existing data on endocrine abnormalities—both in the prenatal and adult stage—in homosexual individuals as well as the evidence concerning sexual orientation in individuals with prenatal hormone disorders. It also discusses various options for future research in the light of new developments in general and behavioral endocrinology. The available endocrine data on male homosexuals versus heterosexuals make it seem highly unlikely that deviations in peripheral hormone levels or hormone production after puberty can be held responsible for the development of male homosexual orientation. Hormone deviations may simply represent an adrenal endocrine response to the psychological situation of female homosexuals or career women, who tend to be overrepresented in homosexual samples. The evidence from intersex patients as well as from the offspring of hormone treated pregnancies, suggests that prenatal hormones contribute to, but do not actually determine, the development of sexual orientation in individuals with abnormal sex hormone histories. The large number of hypothetical neuro-endocrine mechanisms that must be considered in the search for an explanation of homosexuality makes it unlikely that a single mechanism underlies all forms of homosexuality. The great variability of sex-dimorphic and, more specifically, cross-gender behavior patterns in homosexual individuals already makes a universal hormonal mechanism very unlikely and requires, at the very least, an assumption of the modification of hormonal effects by social learning.