Introduction

Recent studies of twins and adoptees have begun to clarify how genetic and environmental factors interact in the development of antisocial behavior. Juvenile delinquency and conduct disorders, adult criminality and antisocial personality disorder, and substance abuse are partly overlapping syndromes, but their genetic relation to one another is uncertain. Antisocial behavior is more common in men than in women, and this sex difference has been helpful to those attempting to understand the transmission and expression of risk for antisocial behavior. In this chapter, we shall review family data from our research programs in St. Louis, Sweden, and Denmark on antisocial behavior and related psychiatric disorders in both men and women with particular attention to recent studies based on general populations of twins and adoptees.

Antisocial personality and related psychiatric disorders

Antisocial personality (ASP) is a disorder manifested by recurrent antisocial and delinquent behavior during adolescence, such as running away from home, fighting, and getting into trouble at school (truancy, suspension, expulsion) as well frequent criminality, poor job performance, and marital instability during adulthood (Guze, 1976; Robins, 1966). Most individuals with uncomplicated ASP commit a small number of petty property offenses during adolescence and early childhood and show little overt criminal behavior after middle age (Bohman, Cloninger, Sigvardsson, & von Knorring, 1982). Those who commit repeated or violent crimes often have alcohol or drug abuse as a complication of their personality disorder.