Using data from 5500 adolescents from the National Longitudinal Study of Adolescent to Adult Health, Domingue et al. (Proc Natl Acad Sci 25:256., 2018) claimed to show that friends are genetically more similar to one another than randomly selected peers, beyond the confounding effects of population stratification by ancestry. The authors also claimed to show 'social-genetic' effects, whereby individuals' educational attainment (EA) is influenced by their friends' genes. We argue that neither claim is justified by the data. Mathematically we show that (1) the genetic similarity reported between friends is far larger than theoretically possible if it was caused by phenotypic assortment as the authors claim; uncontrolled population stratification is a likely reason for the genetic similarity they observed, and (2) significant association between individuals' EA and their friends' polygenic scores for EA is a necessary consequence of EA similarity among friends, and does not provide evidence for social-genetic effects. Going forward, we urge caution in the analysis and interpretation of data at the intersection of human genetics and the social sciences.

中文翻译：

---

由于人口分层，没有证据表明朋友之间的社会遗传效应或遗传相似性：多明格等人（2018 年）的重新评估。

Domingue 等人使用了来自全国青少年到成人健康纵向研究的 5500 名青少年的数据。(Proc Natl Acad Sci 25:256., 2018) 声称除了血统人口分层的混杂影响之外，朋友在基因上比随机选择的同龄人更相似。作者还声称显示出“社会遗传”效应，即个人的受教育程度 (EA) 受其朋友基因的影响。我们认为这两种说法都没有被数据证明是合理的。我们在数学上表明 (1) 如果作者声称是由表型分类引起的，那么朋友之间报告的遗传相似性远大于理论上的可能性；不受控制的种群分层可能是他们观察到的遗传相似性的一个原因，(2) 个人的 EA 与其朋友的 EA 多基因分数之间的显着关联是朋友之间 EA 相似性的必然结果，并没有为社会遗传效应提供证据。展望未来，我们敦促在分析和解释人类遗传学和社会科学交叉点的数据时要谨慎。