This paper extends the understanding of the relation between ADHD and reading comprehension, through examining how this relation differs depending on the quantile an individual falls in for each. Samples from three twin projects around the United States were used (Florida Twin Project, Colorado component of International Longitudinal Twin Study of Early Reading Development, & Western Reserve Reading and Math Projects). Phenotypic analysis using quantile regression showed relations between ADHD related behaviors and reading comprehension to be stronger in the lower quantiles of reading comprehension in two of three samples. A new method was developed extending this analysis into the bivariate genetic space. Results of this quantile genetic analysis revealed that overlapping common environmental influences accounted for a larger proportion of variance in the lower quantiles of these variables in two of three samples. Finally, in all three samples the phenotypic relation was strongest when shared environmental influences accounted for a larger proportion of the overall variance.

本文通过研究这种关系如何根据个体所处的分位数而有所不同，从而扩展了对 ADHD 和阅读理解之间关系的理解。使用来自美国各地三个双胞胎项目的样本（佛罗里达双胞胎项目、国际早期阅读发展纵向双胞胎研究的科罗拉多部分以及西储阅读和数学项目）。使用分位数回归的表型分析显示，在三个样本中的两个样本中，ADHD 相关行为与阅读理解之间的关系在阅读理解的较低分位数中更强。开发了一种新方法，将这种分析扩展到双变量遗传空间。该分位数遗传分析的结果表明，在三个样本中的两个样本中，重叠的共同环境影响在这些变量的下分位数中造成了较大比例的方差。最后，在所有三个样本中，当共同的环境影响占总体方差的较大比例时，表型关系最强。