This study investigated the interactive effects of friend deviance and reward dominance on the development of externalizing behavior of adolescents in the Child Development Project. Reward dominance was assessed at age 16 by performance on a computer-presented card-playing game in which participants had the choice of either continuing or discontinuing the game as the likelihood of reward decreased and the likelihood of punishment increased. At ages 14 and 16, friend deviance and externalizing behavior were assessed through self-report. As expected, based on motivational balance and response modulation theories, path analysis revealed that age 14 friend deviance predicted age 16 externalizing behavior controlling for age 14 externalizing behavior. Reward dominance was a significant moderator of the relationship between friend deviance and externalizing behavior. The contributions of deviant friends to the development of externalizing behavior were enhanced by adolescents' reward dominance.
