In a subsequent set of 2-class GMMs, trajectory class membership was regressed on (1) genotype at each of the 10 SNPs, (2) parental monitoring, and (3) the interaction between (the product of) the specified SNP and parental monitoring. Results of these multivariate analyses are depicted in Table 4. Parental monitoring significantly moderated the influence of genotype on trajectory class membership (P= .007-.03). Table 4 shows class membership by genotype split by parental monitoring. Parental monitoring is divided into high and low groups based on a median split in Table 4 for illustrative purposes, although analyses were conducted using the full quasi-continuous monitoring variable, as described in the methods. The influence of GABRA2 on externalizing trajectory was considerably pronounced under conditions of lower parental monitoring and was diminished under conditions of higher parental monitoring. For example, for SNP rs497068 (again selected for illustration based on being the first SNP in the Table), the percentage of individuals in the elevated persistent externalizing class as a function of number of copies of the minor allele was 10.3%, 12.0%, 16.3%, for individuals with 0,
