behavior. Further, we tested whether this association was moderated by peer group antisocial behavior based on previous twin studies demonstrating that genetic influences on substance use and problem behavior are enhanced as individuals are exposed to higher levels of peer antisocial behavior and substance use (Button et al., 2007; Dick et al., 2007a; Harden et al., 2008). Our hypothesis was supported: the association between CHRM2 and externalizing behavior was exacerbated among those exposed to higher levels of peer group antisocial behavior (Latendresse et al., 2011). These studies illustrate how genotyping genes coming out of gene identification projects in longitudinal, developmental samples can help us understand the pathways of risk associated with those genes. The DNAs for the child development project are currently in Brien Riley's laboratory, making it possible to genotype novel genes coming out of the gene identification projects on which Danielle M. Dick and Brien Riley are involved in this developmental sample. Taking genes that are identified in highly selected, affected populations, and characterizing their risk in community-based samples, across development and in conjunction with experiential and other individual risk and protective factors, will be critical to potentially use genetic information in the future to inform prevention and
