Linking the developing brain with individual differences in clinical and demographic traits is challenging due to the substantial interindividual heterogeneity of brain anatomy and organization. Here we employ an integrative approach that parses individual differences in both cortical thickness and common genetic variants, and assess their effects on a wide set of childhood traits. The approach uses a linear mixed model framework to obtain the unique effects of each type of similarity, as well as their covariance. We employ this approach in a sample of 7760 unrelated children in the ABCD cohort baseline sample (mean age 9.9, 46.8% female). In general, associations between cortical thickness similarity and traits were limited to anthropometrics such as height, weight, and birth weight, as well as a marker of neighborhood socioeconomic conditions. Common genetic variants explained significant proportions of variance across nearly all included outcomes, although estimates were somewhat lower than previous reports. No significant covariance of the effects of genetic and cortical thickness similarity was found. The present findings highlight the connection between anthropometrics as well as neighborhood socioeconomic conditions and the developing brain, which appear to be independent from individual differences in common genetic variants in this population-based sample.

由于大脑解剖结构和组织存在巨大的个体异质性，将发育中的大脑与临床和人口特征的个体差异联系起来具有挑战性。在这里，我们采用综合方法来解析皮质厚度和常见遗传变异的个体差异，并评估它们对一系列广泛的童年特征的影响。该方法使用线性混合模型框架来获得每种类型的相似性及其协方差的独特效果。我们在 ABCD 队列基线样本中的 7760 名无关儿童（平均年龄 9.9 岁，46.8% 为女性）中采用了这种方法。一般来说，皮质厚度相似性和性状之间的关联仅限于身高、体重和出生体重等人体测量学，以及社区社会经济条件的标志。常见的遗传变异解释了几乎所有纳入结果的显着差异，尽管估计值略低于之前的报告。没有发现遗传和皮质厚度相似性影响的显着协方差。目前的研究结果强调了人体测量学以及社区社会经济条件与大脑发育之间的联系，这些联系似乎与基于人群的样本中常见遗传变异的个体差异无关。