Next, structural equation modeling (SEM) was used to test the mediated moderation hypothesis that a SAAF–T × DRD4 interaction effect on increases in protective parenting would mediate, or account for, the SAAF–T × DRD4 interaction effect on substance use. To do this, a SEM model was executed to test the hypothesis that male youths in the SAAF–T condition who carried at least one l allele of DRD4 would experience greater increases in protective parenting from pretest to posttest than would those in the control condition with this genotype or those in either the SAAF–T or control condition who carried two s alleles. Upon confirmation of this hypothesis, a second SEM model was executed to test the mediated moderation hypothesis. The mediated moderation hypothesis would be supported if this model showed (a) a SAAF–T × DRD4 interaction effect on increases in the frequency of substance use, (b) a SAAF–T × DRD4 interaction effect on increases in protective parenting, (c) a link between increases in protective parenting and decreases in youths’ substance use, and (d) a nonsignificant SAAF–T × DRD4 interaction effect
