Not only can genetic influence change in importance for an outcome across time, genetic associations with outcomes can arise through different mechanisms, reflecting the heterogeneous processes by which genotype can be associated with distal behavioral outcomes. Returning to the example of alcohol use, an association has been demonstrated between alcohol use/problem behaviors and a broader dimension of “externalizing” behaviors, which are socially deviant, “acting out” behaviors ranging from conduct disorder in childhood to illicit substance use and antisocial personality disorder in adulthood (Dick et al., 2006b, Verweij et al., 2016). Externalizing behavior in early childhood is a predictor of adult alcohol use (Dick et al., 2013), and may be an early manifestation of how genetic risk for AUDs unfolds, starting with a childhood temperament rather than a direct alcohol use outcome. However, there is also a link between high sociability in childhood and later alcohol use (Dick et al., 2013), indicative of the multiple potential developmental pathways to problem alcohol use that start from underlying genetic predispositions. Understanding how genetic risk unfolds along these pathways is essential to develop effective
