Three sets of preliminary analyses were conducted to examine possible sources of bias in the data. First, we tested for differential attrition between adolescents in analysis (N = 1418) and the full genetic sample (N = 2032) on key sociodemographic characteristics collected at the baseline during the 6th grade. There was no statistical difference for baseline free and reduced lunch (F(1, 2,030) = .30, p = .583), however, there was a difference for baseline parent marital status (F(1, 2,030) = 9.88, p = .002). The Cohen’s d for the differences in parent marital status was d= 0.15, indicating a small difference. Second, using PLINK (v 1.9, Purcell et al., 2007) the Hardy-Weinberg Equilibrium of the OXTR SNPs was tested to determine whether sample allele and genotype frequencies were consistent with Mendelian patterns of inheritance. All five SNPs were in Hardy-Weinberg equilibrium (p-values > 0.05), consistent with accurate genotyping. In addition, the SNPs were not in linkage disequilibrium (r2 < 0.13), indicating that the use of these selected SNPs does not provide redundant information and combined use allows for better coverage
