Department of Psychology, Memorial University of Newfoundland, St. John's A1B 3X9, Newfoundland and Labrador.
Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Cold Spring Harb Perspect Biol. 2022 Aug 1;14(8):a039123. doi: 10.1101/cshperspect.a039123.
In laboratory animals, exposure to gonadal steroid hormones before and immediately after birth can exert permanent effects on many behaviors, particularly reproductive behaviors. The extent to which such effects occur in humans remains an open question, but several lines of evidence indicate that perinatal levels of both androgens and estrogens may affect adult human psychology and behavior, including sexual orientation and gender nonconformity. Some putative indicators of prenatal androgen exposure, including the ratio of the length of the index finger to that of the ring finger (2D:4D), have repeatedly indicated that lesbians, on average, were exposed to more prenatal androgens than straight women, suggesting that sufficient fetal androgen exposure predisposes a fetus to gynephilia (attraction to women) at maturity. The digit ratios of gay men do not differ from those of straight men, suggesting that prenatal androgen levels are not responsible for their androphilia (attraction to men). However, evidence that gay men who prefer an insertive anal sex role (ASR) have more masculine digit ratios than those preferring a receptive ASR suggests that early androgens influence some sexual preferences in men. Furthermore, digit ratios among gay men have been found to correlate with recalled childhood gender nonconformity (CGN). People with isolated gonadotropin-releasing hormone (GnRH) deficiency (IGD) offer further insight into the effects of perinatal gonadal steroid exposure. In people with IGD, gonadal hormone production is low or absent after the first trimester of gestation. However, because placental gonadotropins drive gonadal hormone secretion during the first trimester when genitalia sexually differentiate, individuals with IGD are unambiguously male or female at birth, consistent with their chromosomal and gonadal sex. Men with IGD report greater CGN, again suggesting that perinatal androgen exposure contributes to male-typical behavioral patterns in humans. Interestingly, women with IGD report less androphilia and more bisexuality than control women, suggesting that perinatal ovarian steroids in females typically augment androphilia in adulthood. Taken together, these findings indicate that the perinatal hormonal milieu influences human sexual orientation and gender conformity.
在实验动物中，出生前和出生后立即暴露于性腺类固醇激素会对许多行为产生永久性影响，尤其是生殖行为。这些影响在人类中发生的程度仍然是一个悬而未决的问题，但有几条证据表明，围产期的雄激素和雌激素水平可能会影响成年期人类的心理和行为，包括性取向和性别认同。一些被认为与产前雄激素暴露有关的指标，包括食指与无名指长度的比值（2D:4D），反复表明，同性恋女性平均暴露于更多的产前雄激素，这表明胎儿暴露于足够的雄激素会使胎儿在成熟时对女性产生性偏好（对女性的吸引力）。同性恋男性的数字比率与异性恋男性没有差异，这表明产前雄激素水平不是导致他们对男性有性吸引力（对男性的吸引力）的原因。然而，有证据表明，更喜欢主动肛交角色（ASR）的同性恋男性的数字比率比更喜欢被动 ASR 的男性更高，这表明早期雄激素会影响男性的某些性偏好。此外，同性恋男性的数字比率与他们回忆起的童年性别非认同（CGN）有关。患有孤立性促性腺激素释放激素（GnRH）缺乏症（IGD）的人进一步深入了解围产期性腺类固醇暴露的影响。在患有 IGD 的人中，在妊娠的头三个月后，性腺激素的产生很低或不存在。然而，由于胎盘促性腺激素在生殖器分化时驱动性腺激素分泌，IGD 患者在出生时明确是男性或女性，符合其染色体和性腺性别。患有 IGD 的男性报告称他们的 CGN 更大，这再次表明围产期雄激素暴露会导致人类出现典型的男性行为模式。有趣的是，患有 IGD 的女性比对照组女性报告的雄激素性和双性恋倾向更少，这表明女性围产期卵巢类固醇通常会增强成年期的雄激素性。综上所述，这些发现表明围产期激素环境会影响人类的性取向和性别认同。
