The behavioral genetics of personality disorder

Behavioral genetics research has opened a new window on understanding personality disorder. The earliest studies were focused on establishing the relative contributions of genes and the environment in these disorders. Although these studies provided solid evidence of the importance of genetic and environmental influences on personality disorder and showed that all aspects of personality disorder are subject to genetic influence, heritability studies are limited because they are not helpful in explicating causal mechanisms. More recent research has focused on the relative contributions of the covariation of personality disorder diagnoses and traits, which allows one to examine etiological relationships. These developments are leading to major changes in ideas about what constitutes the environment and nature of the interplay between genes and environment. The present review examines major themes in this growing body of research in the context of current issues in the personality disorders.