Hall Patricia A, Schaeff Catherine M
Department of Psychology, American University, Washington, DC 20016, USA.
Arch Sex Behav. 2008 Feb;37(1):158-65. doi: 10.1007/s10508-007-9282-0.
Previous research suggests that individuals' sexual orientation may be affected by developmental instability (DI) induced by exposure to prenatal stresses. We tested this relationship using fluctuating asymmetry (FA), the small random deviations from symmetry that arise in otherwise bilaterally symmetrical traits as a consequence of developmental noise and developmental instability. Differences among individuals reflect variation in their exposure to and ability to accommodate for stresses experienced during development as well as to developmental noise that arises due to cellular stocasticity. FA measurements for 156 heterosexual and 132 homosexual men and women participants provided strong support for the developmental instability hypothesis: FA was significantly higher in both male and female homosexuals (men: four of seven bilateral traits and composite FA values (cFA); women: five of seven bilateral traits and composite FA values). Although finger-length ratios (FLRs), an indirect marker for prenatal hormones, were sex-atypical (e.g., feminized) for homosexual men, we failed to detect any relationship between FA levels and 2D:4D finger-length ratios (FLRs). Hence, although elevated levels of developmental stress appear to be linked to shifts in sexual orientation, the underlying mechanism does not seem to be connected to sex-atypical prenatal hormones. Additional analyses with sex atypical individuals are needed to confirm this.
先前的研究表明，个体的性取向可能会受到产前压力所引发的发育不稳定性（DI）的影响。我们使用波动不对称性（FA）来测试这种关系，波动不对称性是指在原本双侧对称的性状中，由于发育噪声和发育不稳定性而出现的与对称性的微小随机偏差。个体之间的差异反映了他们在发育过程中所经历的压力暴露程度和应对能力的差异，以及由于细胞随机性而产生的发育噪声的差异。对156名异性恋和132名同性恋男性和女性参与者进行的FA测量，为发育不稳定性假说提供了有力支持：男性和女性同性恋者的FA均显著更高（男性：七个双侧性状中的四个以及综合FA值（cFA）；女性：七个双侧性状中的五个以及综合FA值）。尽管手指长度比（FLR）作为产前激素的间接标志物，对于同性恋男性来说是性别非典型的（例如，女性化），但我们未能检测到FA水平与2D:4D手指长度比（FLR）之间存在任何关系。因此，尽管发育压力水平的升高似乎与性取向的转变有关，但其潜在机制似乎与性别非典型的产前激素并无关联。需要对性别非典型个体进行额外分析来证实这一点。
