In summary, findings from these three studies provide the first empirical evidence in youth, consistent with the DSH, that genetically susceptible individuals are more responsive to the full range of environmental contexts, and exhibit enhanced outcomes under positive/supportive contexts and poorer outcomes under negative environments. The association between positive/supportive parenting and youths' level of positive affect in children and adolescents was significant only among youth carrying two short alleles, but not those carrying a long allele, of 5-HTTLPR. Consequently, 5-HTTLPR may confer susceptibility to environmental context for positive affectivity among the youth.
