Abstract
A body of research has revealed that low self-control is one of the strongest and most consistent predictors of antisocial behaviors. As a result, there is great interest in identifying the factors that cause variation in levels of self-control. Much of this work has centered on identifying the effects that social factors, such as parental socialization, have on self-control. More recently, however, there has been research revealing that levels of self-control are scripted by genetic factors as well as environmental factors. The current study examines whether a polymorphism (5HTTLPR) in the serotonin transporter gene and exposure to delinquent peers are associated with levels of self-control. Analysis of the National Longitudinal Study of Adolescent Health indicates that the 5HTTLPR polymorphism interacted with a measure of delinquent peer affiliation to predict variation in self-control during adolescence and adulthood. Implications for theories of crime causation are discussed.