Reply to Abdellaoui et al.: Interpreting GAM

Abdellaoui et al. (1) question our (2) finding that spouses are more genetically similar than nonspouses because they believe that we are only measuring ethnically based social sorting indexed by population stratification and not genetic assortative mating (GAM). To address this possibility, we evaluated GAM among a racially homogeneous group, we adjusted for genetic variation with principal components (PCs), and we adjusted for geographic region. One of these results, based on direct controls for PCs, where the residualized GAM was not significantly different from zero, is the primary focus of their critique. The main thrust …