The Multifactorial Model of Disease Transmission: II. Sex Differences in the Familial Transmission of Sociopathy (Antisocial Personality)

Abstract
Summary: Sociopathy is highly familial in both white and black families. Sociopathy in men and women clusters in the same families, but is much more frequent in men than in women. It is more prevalent among relatives of sociopathic women than among relatives of sociopathic men. The sex difference in its prevalence appears to be due to sex-related cultural or biological factors causing the threshold to be more deviant in women. There is no evidence of a genetic difference in its prevalence and transmission according to race.The two-threshold Multifactorial Model of Disease Transmission provides an explanation for the striking sex difference in the transmission of sociopathy. Such a pattern of transmission is obtained only in diseases whose genetic component is polygenic or, if only one or a few genotypes are relevant, where each of these has a small effect relative to environmental factors.Assortative mating accounts for a large proportion of the observed similarity between relatives. However, the familial clustering of male and female sociopaths is not dependent on assortative mating.The high correlation among siblings that is expected under conditions of random mating indicates that environmental factors common to siblings contribute to the aetiology of sociopathy. The greater deviance of the parental home experiences of sociopathic women compared to sociopathic men is further evidence of the importance of familial environment.