Personality and the immune system: models, methods, and mechanisms.

A relationship between personality and the immune system has been hypothesized for at least 25 years, and understanding this relationship could contribute to understanding how personality affects the onset and course of chronic diseases such as cancer and heart disease. A number of personality dimensions, including repression, optimism, hostility, attributional style, and extraversion-introversion, have been related to immune parameters or immunity. Theoretical and methodological issues in interpreting the extant literature and in planning future research include selection of personality dimensions to study, study design, and attention to potential psychosocial mediators. Past and future investigations using sophisticated theory and methodology to investigate the ongoing influence of personality on physiological systems, including the immune system, promise to advance the understanding of both.