Third, despite the basic heuristic utility of this emergent framework, one element that has been missing from most discussions linking adolescent brain development and behavior is the context in which adolescents live. Here I am not referring so much to the impact of context on brain development (although, as noted earlier, the likely plasticity of the adolescent brain makes this a crucial issue for future study), but the role of context in moderating the way that neural influences are expressed. The heightened vulnerability of middle adolescence will have different consequences in different settings, both as a function of available opportunities to engage in reward-seeking, and as a function of the degree to which external agents regulate adolescents whose self-regulation is still maturing. With respect to reward-seeking, as Dahl (2004) has noted, there are many ways for adolescents to satisfy their inclinations toward sensation-seeking that are not harmful or antisocial. And with respect to self-regulation, the degree to which adolescents engage in risky behavior is in part a function of opportunities to access substances and circumstances that place them at risk.
