His work investigates the structure and measurement of personality, emotion and psychopathology, as well as examining how personality traits relate to clinical disorders. He works in a variety of substantive areas within psychopathology, including the emotional disorders (which include the depressive disorders, anxiety disorders, bipolar disorders, posttraumatic stress disorder, and obsessive-compulsive disorder), the personality disorders, schizotypy, and dissociation. The long-term goal of this work is to develop comprehensive taxonomic models that integrate normal-range and pathological processes into a single overarching scheme. Other areas of personality research examine temporal stability versus change across the life span; mate preferences and interpersonal attraction; and accuracy versus bias in person perception.