The purpose of this chapter is to provide an overview of the behavior and molecular genetics of personality disorder. We begin with a thorough review of findings from the field of behavior genetics of personality pathology, including univariate twin studies, multivariate twin studies, and new models of gene–environment interplay. We then discuss the molecular genetics of personality pathology, including a consideration of candidate gene analysis, linkage analysis, and genome-wide association studies. We focus in particular on research concerning antisocial personality disorder (including antisociality and aggression), borderline personality disorder, schizotypal personality disorder, Cluster B and C personality disorders, and normal personality traits. We then provide a discussion of challenges and future directions with respect to behavior and molecular genetic research. We conclude the chapter with a discussion of the implications of this research for the forthcoming fifth edition of the American Psychiatric Association’s diagnostic manual.
