Genomic ancestry, cognitive ability, and socioeconomic outcomes

The cause(s) of ubiquitous cognitive differences between American self-identified racial / ethnic groups (SIREs) is uncertain. Evolutionary-genetic models posit that ancestral genetic 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-genetic models of group differences, but also with certain environmental models which mimic the predictions of evolutionary-genetic 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之成因尚不明确。进化遗传模型提出，先祖遗传选择压力是这些差异的最终根源。相反，社会学模型则认为这些差异源于种族歧视。为检验基于这些模型的理论预测，我们采用全球混合分析的方法，利用来自儿童影像、神经认知与遗传研究（PING；样本量 N = 1,369 名美国儿童）的数据进行了研究。具体而言，我们运用遗传流行病学的方法，旨在确定遗传起源是否对认知能力有显著预测作用，且这种作用独立于SIRE。在采用四种不同编码方式将SIRE作为协变量进行回归模型分析时，我们发现遗传起源与一般认知能力和父母社会经济地位（SES）之间存在渐进性的关系。当将父母SES加入预测变量，并将认知能力作为结果变量时，全球起源与认知能力之间的关系部分减弱。此外，在单独分析子群体时，这些关联通常依然成立。我们的研究结果与群体差异的进化遗传模型相一致，同时也与某些模拟进化遗传模型预测的环境模型相吻合。本文对美洲种族/民族差异研究的影响进行了讨论，并探讨了进一步探讨这一问题的方法。