For illustrative purposes, data from the fifth SNP in Table 4 (rs1455858) indicate that among adolescents with a “AA” genotype (i.e., with two copies of adenine and zero copies of the “G” variant, guanine), 79% are likely to display relatively low initial levels of externalizing problems that decline throughout adolescence, 16% are likely to display somewhat more moderate initial levels that also decrease over time, and only 5% are likely to display persistently high levels of externalizing problems. In comparison, adolescents with the “GG” genotype still have the highest likelihood of belonging to the decreasing low externalizing trajectory, though much less so than their homozygous “AA” counterparts (53% versus 79%). In addition, “GG” adolescents are more than twice as likely as “AA” adolescents to be probabilistically assigned to the decreasing moderate trajectory (37% versus 16%), and two times as likely to display a persistently high pattern of externalizing problems (10% versus 5%). Genotype (modeled additively) was not predictive of relative differences in the odds of membership in the moderate decreasing versus stable high externalizing trajectories. Of note, a parallel analysis with probability of trajectory class membership regressed on peer group antisocial behavior yielded no evidence of association.
