Genetic and environmental factors in adoptee antisocial personality.

In a sample of 286 adult male adoptees 44 met criteria for antisocial personality (ASP). Two types of biologic parent background were associated with increased incidence of ASP in offspring: those with alcohol problem and those with a criminal conviction or adjudged delinquency. ASP adoptees were also significantly more likely to be alcoholic. Log linear modeling showed that alcohol problems in a biologic parent predicted increased alcohol abuse in the adoptee and that criminality/delinquency in a biologic parent predicted adult adoptee ASP. In the log-linear model two environmental factors significantly increased adoptee ASP: (1) placement in an adoptive home where there was an alcohol problem or antisocial behavior; and (2) placement in a lower socioeconomic home when the adoptee came from a background of criminality/delinquency in a biologic parent. When the adoptee did not have this biologic background socioeconomic level appeared to have little effect on ASP incidence. The results suggest the importance of genetic-environmental interaction in the genesis of adult ASP disorder.