Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninsky pr., 32a, Moscow, Russia, 119991.
National Research University Higher School of Economics, Moscow, Russia.
Sci Rep. 2021 Apr 14;11(1):8157. doi: 10.1038/s41598-021-87394-6.
Recently, a number of authors have claimed that sexual dimorphism in the second-to-fourth digit ratio (2D:4D) is simply dependent on digit length and is an artifact of allometry. The goal of our study is to verify the validity of these assumptions. The study sample comprised 7,582 individuals (3,802 men and 3,780 women) from three large world populations: Europeans (n = 3043), East Africans (n = 2844), and Central Asians (n = 1695). The lengths of the second and fourth digits on both hands were measured. Digit ratios were computed according to standard procedures. Analyses were conducted separately for each hand for the whole sample and in succession for the three large populations. Additionally, we separately tested four age cohorts (≤ 13, 14-18, 19-30, and 31 ≥ years) to test the effect of developmental allometry. The second and fourth digits showed strong positive linear relationships on both hands, and demonstrated an increase with age; digit length in women from the youngest age cohort was longer or equal to that of men, and shorter than men in older age cohorts. However, the 2D:4D magnitude and its sexual dimorphism remained stable throughout the ontogeny. To test for an allometric effect on 2D:4D, the average digit lengths were calculated. Both sex and population origin were permanent reliable predictors of 2D:4D, whereas average digit length was not. Height was applied as another measure of allometric effect on the limited sample (≤ 30 years) from the European population, along with sex and age. No allometric effect was observed in this case. We conclude that sex differences in 2D:4D are not an artifact of allometry.
最近，一些作者声称，第二至第四指长比（2D:4D）的性别二态性仅仅取决于指长，是一种比测的假象。我们研究的目的是验证这些假设的有效性。研究样本包括来自三个大的世界人群的 7582 个人（3043 名男性和 3780 名女性）：欧洲人（n=3043）、东非人（n=2844）和中亚人（n=1695）。测量了双手的第二和第四指的长度。根据标准程序计算指比率。我们分别对整个样本和三个大人群的每只手进行了分析。此外，我们分别测试了四个年龄组（≤13、14-18、19-30 和 31≥岁），以检验发育比测的影响。双手的第二和第四指显示出强烈的正线性关系，并随着年龄的增长而增加；在最年轻的年龄组中，女性的指长比男性长或相等，而在年龄较大的年龄组中则比男性短。然而，2D:4D 的大小及其性别二态性在整个个体发育过程中保持稳定。为了检验 2D:4D 上的比测效应，我们计算了平均指长。性别和人口来源是 2D:4D 的永久可靠预测因子，而平均指长不是。身高被用作欧洲人群中（≤30 岁）有限样本上比测效应的另一种衡量标准，同时考虑了性别和年龄。在这种情况下，没有观察到比测效应。我们的结论是，2D:4D 中的性别差异不是比测的假象。
