Halsey Lewis G, Esteves Gabriel P, Dolan Eimear
School of Life and Health Sciences, University of Roehampton, London SW15 4JD, UK.
Applied Physiology and Nutrition Research Group, Center of Lifestyle Medicine, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, SP, Brazil.
R Soc Open Sci. 2023 Sep 6;10(9):230713. doi: 10.1098/rsos.230713. eCollection 2023 Sep.
Many researchers presume greater variability between female participants than between males due to the menstrual cycle. This view has encouraged a sex bias in health and medical research, resulting in considerable knowledge gaps with important clinical implications. Yet in another field-evolutionary biology-the received wisdom is the reverse: that men are more variable, possibly due to male heterogamety. To test these competing hypotheses, we compared variance between the sexes for 50 morphological and physiological traits, analysing data from the NHANES database. Nearly half the traits did not exhibit sexual dimorphism in variation, while 18 exhibited greater female variation (GFV), indicating GFV does not dominate human characteristics. Only eight traits exhibited greater male variation (GMV), indicating GMV also does not dominate, and in turn offering scant support for the heterogamety hypothesis. When our analysis was filtered to include only women with regular menstrual cycles (and men of equivalent age), the number of traits with GFV and GMV were low and not statistically different, suggesting that the menstrual cycle does not typically explain GFV when it occurs. In practical terms, health and medical researchers should no longer simply assume that female participants will induce additional variation in the traits of interest.
许多研究人员推测，由于月经周期的缘故，女性参与者之间的变异性比男性之间更大。这种观点助长了健康和医学研究中的性别偏见，导致了存在重要临床意义的相当大的知识空白。然而，在另一个领域——进化生物学——普遍的看法却相反：男性变异性更大，这可能是由于男性的异配性。为了检验这些相互竞争的假设，我们比较了50种形态和生理特征在两性之间的方差，分析了来自美国国家健康和营养检查调查（NHANES）数据库的数据。近一半的特征在变异性上没有表现出两性差异，而18种特征表现出更大的女性变异性（GFV），这表明GFV并不主导人类特征。只有8种特征表现出更大的男性变异性（GMV），这表明GMV也不占主导地位，进而为异配性假设提供的支持很少。当我们的分析只纳入月经周期规律的女性（以及年龄相当的男性）时，表现出GFV和GMV的特征数量很少且无统计学差异，这表明月经周期通常并不能解释GFV的出现。实际上，健康和医学研究人员不应再简单地假定女性参与者会在感兴趣的特征上引发额外的变异性。
