In psychology, trait theory is a major approach to the study of human personality. Trait theorists are primarily interested in the measurement of traits, which can be defined as habitual patterns of behavior, thought, and emotion. According to this perspective, traits are relatively stable over time, differ among individuals, and influence behavior. This book presents data on personality trait research including narcissistic and borderline personality traits and their relationship with childhood abuse experiences; personality disorders and subjective well-being; male body image and eating disorders; personality traits in relation to entrepreneurship research and the relationship between lay conceptions of intelligence and personality traits.