School of Psychology, Faculty of Medical Sciences, Newcastle University, 4.32 Dame Margaret Barbour Building, Wallace Street, Newcastle upon Tyne, UK.
Department of Psychology, University of Cambridge, Cambridge, UK.
Sci Rep. 2022 Aug 9;12(1):13586. doi: 10.1038/s41598-022-17247-3.
The ratio of index to ring finger (2D:4D) has been hypothesised to indicate prenatal androgen exposure, yet evidence for its validity is lacking. We report the first pre-registered study to investigate mothers' early pregnancy sex hormone concentrations in relation to their children's digit ratios measured at 18-22-month follow-up. Although the testosterone (T) to estradiol (E) ratio correlated negatively with right hand digit ratio (R2D:4D) and directional asymmetry (right-minus-left) in digit ratio (D), neither effect remained statistically significant once demographic and obstetric covariates were controlled for. Nevertheless, the multivariate level of analysis did reveal that T correlated positively with left hand digit ratio (L2D:4D) and negatively with D. However, the first of these effects is in the opposite direction to that predicted by theory. Taken together, the results of our study suggest research with larger samples is required to determine whether digit ratios are valid proxies for maternal sex hormone exposure.
食指与无名指长度之比（2D:4D）被假设可以反映胎儿期雄激素暴露情况，但目前缺乏其有效性的证据。我们报告了第一项预先注册的研究，旨在调查母亲在妊娠早期的性激素浓度与她们孩子在 18-22 个月随访时的手指比例之间的关系。尽管睾酮（T）与雌二醇（E）的比值与右手手指比例（R2D:4D）和手指比例的方向性不对称（右-左）呈负相关，但在控制了人口统计学和产科协变量后，这两种影响都不再具有统计学意义。然而，多变量分析确实表明，T 与左手手指比例（L2D:4D）呈正相关，与 D 呈负相关。然而，其中第一个效应与理论预测的方向相反。综上所述，我们的研究结果表明，需要进行更大样本的研究，以确定手指比例是否可以作为母体性激素暴露的有效替代指标。
