but not undesirable peers (Guyer et al., 2009). Without an appropriate manipulation of the socially desirable peers as rewarding stimuli, it is impossible to know if, indeed, adolescents find socially desirable peers more rewarding than others but this study does implicate dopamine-rich circuitry in adolescent sensitivity to social interactions. As such, what is rewarding and the context in which the rewards are presented are important factors to consider when comparing motivation, behavior and underlying reward circuitry in adolescents relative to other groups. This is particularly relevant to the well-characterized risk-taking behavior in adolescents (Steinberg, 2004). Relative to adults or children, adolescents are more likely to categorize risk-taking as “fun” or rewarding (Maggs et al., 1995); this suggests that in response to a risky opportunity, adolescents may be more likely to engage the dopamine system than other age groups, which may contribute to their increased risk-taking tendencies. This phenomenon has been reviewed extensively elsewhere (e.g., Steinberg, 2004; Ernst and Mueller, 2008; Somerville et al., 2009).
