Genomic ancestry, cognitive ability and socioeconomic outcomes

The cause of ubiquitous cognitive differences between American self-identified racial / ethnic groups (SIREs) is uncertain. Evolutionary models posit that ancestral selection pressures are the ultimate source of these differences. Conversely, sociological models posit that these differences result from racial discrimination. To examine predictions based on these models, we conducted a global admixture analysis using data from the Pediatric Imaging, Neurocognition, and Genetics Study (PING; N = 1,369 American children). Specifically, we employed the methodology of genetic epidemiology to determine whether genetic ancestry significantly predicts cognitive ability, independent of SIRE. In regression models using four different codings for SIRE as a covariate, we found incremental relationships between genetic ancestry and both general cognitive ability and parental socioeconomic status (SES). The relationships between global ancestry and cognitive ability were partially attenuated when parental SES was added as a predictor and when cognitive ability was the outcome. Moreover, these associations generally held when subgroups were analyzed separately. Our results are congruent primarily with evolutionary models of group differences, but also with certain environmental models which mimic the predictions of evolutionary ones. Implications for research on race / ethnic differences in the Americas are discussed, as are methods for further exploring the matter.

美国自我认同的种族/民族群体（SIREs）之间普遍存在的认知差异成因尚不明确。进化模型认为，祖先选择压力是这些差异的终极来源。相反，社会学模型则认为这些差异源于种族歧视。为了检验这些模型所提出的预测，我们利用来自儿童影像学、神经认知和遗传学研究（PING；N = 1,369 名美国儿童）的数据，进行了一次全球混血分析。具体而言，我们采用了遗传流行病学的方法，以确定遗传血统是否在SIRE之外显著预测认知能力。在以SIRE作为协变量的四个不同编码的回归模型中，我们发现遗传血统与一般认知能力和父母社会经济地位（SES）之间存在增量关系。当将父母SES作为预测变量和认知能力作为结果变量时，全球血统与认知能力之间的关系部分减弱。此外，当对子群体分别进行分析时，这些关联通常仍然成立。我们的研究结果主要与群体差异的进化模型相吻合，但也与某些模拟进化模型预测的特定环境模型相一致。本文讨论了美洲种族/民族差异研究的影响，以及进一步探讨该问题的方法。