Individual differences, immunity, and cancer: lessons from personality psychology.

Individual differences have an important role in modulating the relationship between environmental events such as stressors and the immune system, and stable individual differences such as personality may have an important influence not only on immunity but on the progression of chronic health problems such as cancer. However, the relationships among personality, the immune system, and health-especially cancer-are controversial. Looking back to another controversy may help inform future research in this area: In the 1960s, Walter Mischel questioned whether stable personality traits existed. Responses to this challenge included research designs that improved reliability and accounted for both person and situation in an interactionist model. Both responses are relevant to current research in personality, immunity, and health.