Whereas children receiving A/A genotype showed reductions in externalizing behavior regardless of intervention format, for G allele carriers, the individual format of the intervention was more effective; carriers of the G allele did not respond well to the group format. This finding may be indicative of this gene’s influence on social cognition and behavior. Given that the A allele of rs2268493 has previously been associated with conditions involving reduced social bonding (Beitchman et al., 2012; D. B. Campbell et al., 2011; Di Napoli et al., 2014; Yrigollen et al., 2008), it may be that in the context of a group-based intervention, individuals homozygous for this allele were less sensitive to the effects of deviant peers and were less likely to bond with and be influenced by other at-risk children in the group; thus, children with the A/A genotype were able to benefit from the group-based intervention. In contrast, carriers of the G allele did not demonstrate significant reductions in teacher-reported externalizing behavior over the course of the intervention, suggesting that for these individuals, the beneficial effects of the intervention may
