Research has documented a strong association between early adolescent problem behavior and adult disinhibitory psychopathology, leading some to suggest that the latter can be reduced by preventing or delaying the former. But the prevention implications of this association necessarily depend upon the causal mechanisms that produce it. The current study was designed to test implications of a model that posits that early problem behavior and disinhibitory psychopathology are associated because they are both manifestations of a common inherited liability. At their age-17 assessment, 1080 twins from the older cohort of the Minnesota Twin Family Study reported whether and the age at which they first: drank alcohol, used tobacco, used illicit drugs, had sexual intercourse, and had police contact. An Early Problem Behavior index was computed by summing the number of these experiences each participant reported having before age 15. Outcome measures of disinhibitory psychopathology were assessed by clinical interview at the age-20 follow-up and included number of symptoms of nicotine dependence, alcohol abuse and dependence, drug abuse and dependence, and adult antisocial behavior. Biometric analysis of the multivariate twin data showed that: (1) early adolescent problem behavior is weakly heritable (approximately 20%), (2) the common factor underlying disinhibitory psychopathology is strongly heritable (approximately 75%), and (3) the phenotypic correlation between early adolescent problem behavior and disinhibitory psychopathology was strong (approximately 0.60) and accounted for primarily by genetic factors common to the two domains. Findings are discussed in the context of research on the prevention and developmental nature of substance use disorders and related psychopathology.