Larson and Asmussen, 1991) and also appear to experience the same positive situations as less pleasurable than adults (as based on self-reports) (Watson and Clark, 1984). Adolescents also find sweetness (sugar) less pleasant than children (DeGraff and Zandstra, 1999). Based on these data, some speculate that adolescents may generally attain less positive feelings from rewarding stimuli, which drives them to purse new appetitive reinforcers through increases in reward-seeking that increase activity in dopamine-related circuitry (Spear, 2000). An opposing theory postulates that disproportionately increased activation of the ventral striatal dopamine circuit (that is, the increased dopaminergic release in response to rewarding events during adolescence) underlies adolescent reward-related behavior (Chambers et al., 2003). This view arises from extensive work on dopamine and its principal role in the translation of encoded motivational drives into action (Panksepp, 1998). This theory posits that adolescent behavior is driven by reward-related appetitive systems. Based on a majority of the work reviewed below, the field has generally converged on this latter theory; that is, that adolescents are, in part, motivated to engage in high reward behaviors because of developmental changes in the striatum that confer hypersensitivity to reward (e.g., Ernst et al., 2009). However, data in support of
