Hruschka Daniel J, Hackman Joseph V, Stulp Gert
School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, United States.
School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, United States.
Econ Hum Biol. 2019 Aug;34:239-251. doi: 10.1016/j.ehb.2018.12.005. Epub 2018 Dec 20.
Contemporary humans occupy the widest range of socioeconomic environments in their evolutionary history, and this has revealed unprecedented environmentally-induced plasticity in physical growth. This plasticity also has limits, and identifying those limits can help researchers: (1) parse when population differences arise from environmental inputs or not and (2) determine when it is possible to infer socioeconomic disparities from disparities in body form. To illustrate potential limits to environmental plasticity, we analyze body mass index (BMI) and height data from 1,768,962 women and 207,341 men (20-49 y) living in households exhibiting 1000-fold variation in household wealth (51 countries, 1985-2017, 164 surveys) across four world regions-sub-Saharan Africa, South Asia, Latin America, and North Africa and the Middle East. We find that relationships of environmental inputs with both mean height and BMI bottom out at roughly 100-700 USD per capita household wealth (2011 international units, PPP), but at different basal BMIs and basal heights for different regions. The relationship with resources tops out for BMI at around 20 K-35 K USD for women, with growth potential due to environmental inputs in the range of 6.2-8.4 kg/m. By contrast, mean BMI for men and mean height for both sexes remains sensitive to environmental inputs even at levels far above the low- and middle-income samples studied here. This suggest that further work integrating comparable data from low- and high-income samples should provide a better picture of the full range of environmental inputs on human height and BMI. We conclude by discussing how neglecting such population-specific limits to human growth can lead to erroneous inferences about population differences.
当代人类在其进化史上占据了最广泛的社会经济环境范围，这揭示了前所未有的环境诱导身体生长可塑性。这种可塑性也有其限度，识别这些限度有助于研究人员：（1）分析群体差异何时源于环境因素，（2）确定何时能够从体型差异推断社会经济差距。为了说明环境可塑性的潜在限度，我们分析了来自撒哈拉以南非洲、南亚、拉丁美洲以及北非和中东这四个世界区域的1768962名女性和207341名男性（20至49岁）的体重指数（BMI）和身高数据，这些人生活在家庭财富相差1000倍的家庭中（51个国家，1985 - 2017年，164项调查）。我们发现，环境因素与平均身高和BMI的关系在人均家庭财富约100 - 700美元（2011年国际单位，购买力平价）时趋于平稳，但不同区域的基础BMI和基础身高不同。女性BMI与资源的关系在约20K - 35K美元时达到顶峰，环境因素导致的生长潜力在6.2 - 8.4kg/m范围内。相比之下，男性的平均BMI以及男女两性的平均身高即使在远高于此处研究的低收入和中等收入样本水平时，仍对环境因素敏感。这表明，整合来自低收入和高收入样本的可比数据的进一步研究，应能更全面地呈现环境因素对人类身高和BMI的影响。我们在结论中讨论了忽视人类生长的这种群体特异性限度如何导致对群体差异的错误推断。
