Predisposition to petty criminality in Swedish adoptees. I. Genetic and environmental heterogeneity.

The inheritance of criminality was studied in 862 Swedish men and adopted by nonrelatives at an early age. If type of offense and association with alcohol abuse were neglected, criminality was heterogeneous and appeared to be largely nonfamilial. Nevertheless, different genetic and environmental antecedents influenced the development of criminality, depending on whether or not there was associated alcohol abuse. Alcoholic criminals often committed repetitive violent offenses, whereas nonalcoholic criminals were characterized by commission of a small number of petty property offenses. These nonalcoholic petty criminals had an excess of biologic parents with histories of petty crime but not alcohol abuse. In contrast, the risk of criminality in alcohol abusers was correlated with the severity of their own alcohol abuse, but not with criminality in the biologic or adoptive parents. Unstable preadoptive placement was associated with increased risk for petty criminality, whereas low social status was associated with alcohol-related criminality. We discuss the significance of these results in relation to the classification of criminals and current concepts about antisocial personality.