This research blends 2 traditions of theorizing on the causes of crime, one focused on the role of individual differences and the other focused on structural and contextual variables. Two related studies examined the relations among impulsivity, neighborhood context, and juvenile offending. The first, cross-sectional study uses a large sample of 13-year-old inner-city boys, whereas the second, longitudinal study offers a conceptual replication using 17-year-old inner-city boys who are a subset of the original sample. Across both studies, results indicate that the effects of impulsivity on juvenile offending are stronger in poorer neighborhoods. Furthermore, nonimpulsive boys in poor neighborhoods were at no greater risk for delinquency than nonimpulsive boys in better-off neighborhoods. In this article, we bring together two major traditions of theorizing about the causes of antisocial behavior. The first tradition, with strong links to psychology and psychiatry, seeks to explain crime by using the individual characteristics of offenders. Theories in this tradition suggest that individuals commit crimes because they possess certain psychological qualities that make them more liable to commit crime. Such accounts are identifiable as early as the turn of the 19th century, when psychiatrists described pyromania and kleptomania as distorted personality constellations (Binder, 1987). Modern theorists have linked criminal offending to