To test variance/covariance equivalence, we conducted a multivariate analysis of variance using all model variables as dependent variables (parent and child interparental conflict and positivity, threat appraisal, internalizing problems) and DRD4 status as the fixed effect. Box’s M was statistically significant (M = 36.10; F(21, 270,897) = 1.69, p < .05) indicating overall (or omnibus) heterogeneity in variances/covariance between genotypes. As an additional check, we conducted a second multivariate analysis of variance similar to the first but substituting PROSPER intervention condition (0 = control, 1 = intervention) as the fixed effect. Box’s M was not statistically significant (M = 29.82), F(21, 367,153) = 1.40, ns. This result suggests the current findings are not conditioned by intervention participation.
