Descriptive statistics for all non-genetic study variables are presented in Table 2. Sample means, standard deviations, and response ranges are reflected on the diagonal for the nine time-specific raw externalizing scores used in the derivation of externalizing trajectories, and for adolescents’ reports of their peer group’s antisocial behavior. Bivariate associations between these variables are depicted off-diagonal, via Pearson’s correlation coefficients. Not surprisingly, externalizing scores increased into mid-adolescence and decreased thereafter, with relatively stable levels of variability across time. Moreover, associations between these variables were strong, particularly among those closest in temporal proximity, but diminished in magnitude as the time between measurements increased. Notably, no significant associations were found between the any of the nine SNPs in CHRM2 and peer group antisocial behavior.
