This volume presents a scholarly analysis of psychopathic and sociopathic personalities and the conditions that give rise to them. In doing so, it offers a coherent theoretical and developmental analysis of socialization and its vicissitudes, and the role played in socialization by the crime-relevent genetic traits of the child and the skills and limitations of the primary socializing agents, the parents. The author states that crime - the failure of socialization - is rare among traditional peoples still living in the extended-family environment in which our common ancestors lived and to which our species is evolutionarily adapted. The author demonstrates that the sharp rise in crime and violence in the US since the 1960s can be attributed to the coeval increase in divorce and illegitimacy which has left millions of fatherless children to be reared by over-burdened, often immature or sociopathic mothers. The genus "sociopathic personality" includes those persons whose failure of socialization can be attributed largely to indifferent or incompetent rearing. Two generalizations supported by modern behaviour genetic research are that most psychological traits have strong genetic roots and lasting influence of the rearing environment. This book demonstrates that the important trait of socialization is an exception. Although traits that obstruct or facilitate socialization itself is only weakly heritable; this is because modern American society displays such enormous variance in the relevant environmental factors, mainly in parental competence. Moreover, parental incompetence that produces sociopathy contributes far more to crime and violence than psychopathy because sociopaths are much more numerous and because sociopathy is a familial trait for both genetic and environmental reasons.