A body of empirical research has revealed that neuropsychological functioning is one of the most consistent predictors of antisocial behavior. It is somewhat surprising however that criminological research has been slow to examine the different factors that are implicated in the development of neuropsychological deficits. This study addresses this gap in the literature by examining the effects that a number of social and biological variables have on neuropsychological functioning. Analysis of the National Longitudinal Study of Adolescent Health (Add Health) indicates that postnatal exposure to cigarette smoke, duration of breastfeeding, maternal involvement, and household income predicts variation in adolescent and adulthood levels of neuropsychological functioning. Implications of the findings are noted and discussed.