Invited essay: the challenge of differentiating normal and disordered personality

By separating personality disorders from other psychiatric conditions and requiring mental health professionals to assess the personalities of all their patients, DSM-III Axis II created an explosion of ideas and research on the nature and structure of personality. Since 1980, theorists and researchers from previously segregated camps have come together to address a number of important taxonomic issues, including the relationship between normal and disordered character. In this article, we place the challenge of differentiating normal and abnormal personality in historical perspective, and outline major theories, models, and methods that inform personologists in their quest. The complexity of personality, and the differences in the way people view the subject matter, ensure that there will be several research lines in the next generation. Progress in the field can be quickened by refinements in theory, the development of more assessment instruments that tap both normal and abnormal traits, and empirical studies that follow well-match groups of normals and patients over significant time periods.