Early difficulties in assimilating social norms may be due to various reasons, both organismic and environmental. These groups of reasons are not independent of each other. O'Connor et al. (1998) found that 7–12-year old adopted youth at high risk for antisocial disorder (based on the biological parent status) evoked negative and coercive parenting from their adoptive non-antisocial parents. In turn, parenting style, as perceived by the child, is predictive of childhood disruptive behavior disorders (conduct disorder and attention deficit hyperactivity disorder) (Vanyukov et al., 2007), known to be frequent precursors of SUD. Importantly, for CD, the more potent predictor of SUD, this relationship has different directions for fathers and mothers. These relationships may also be influenced by a functional polymorphism in the MAOA gene coding monoamine oxidase A, a key enzyme in the metabolism of amine neurotransmitters (e.g., dopamine, serotonin). Although the individuals with early-onset antisociality/underarousal/low-AAS are a minority, by negating societal (parental) norms they constitute a highly charged social nucleus attracting adolescents who come into contact with it, real or virtual—unless protected genetically, by upbringing, and/or by social environment.
