Testosterone

Abstract

Testosterone (T) is a sex steroid associated with sexual behavior and libido in both male and female human and nonhuman primates. T also mediates the trade‐off between mating effort and parenting effort in males. Experimental work has established that both prenatal and adult exposure to T are critical for the full expression of male sexual behaviors in nonhuman primates. In addition, work in the common marmoset has found that male T levels vary in response to both potential mates and infants. In humans, T is critical to the expression of libido in both men and women. Furthermore, male T levels are responsive to both romantic relationships and fatherhood, suggesting a parallel with nonhuman primates. Women with congenital adrenal hyperplasia show increased rates of same‐sex orientation, which is thought to reflect the impact of prenatal androgens on the brain in utero.