Evidence that personality characteristics predict important physical health outcomes has contributed to a resurgence in personality science over the past several decades (Roberts, Kuncel, Shiner, Caspi, & Goldberg, 2007;Smith & MacKenzie, 2006). Replicated, rigorous studies in which personality traits and processes predict longevity, the development of serious illnesses, and survival among the medically ill have gone far in addressing prior criticisms that personality concepts and measures have limited utility (cf. Mischel, 1968). Yet, much of this research has important limitations, and key questions remain unanswered.Specifically, associations of individual, separately considered personality traits with health outcomes are an important type of evidence, but such studies ignore the likely overlapping effects of seemingly distinct personality characteristics as well as the aggregation of risk factors that involve personality with those that reflect the social environment. Given the reciprocal associations between personality and social life (e.g., Caspi, Roberts, & Shiner, 2005; M. L. Cooper, 2002), effects of personality on health likely are intertwined with aspects of personal relationships and social environments known to influence health (e.g., Holt-Lunstad, Smith, & Layton, 2010). Hence, a more integrative view of personality as a central component of more broadly defined psychosocial risk is needed. Research also must identify mechanisms underlying such associations, to better guide risk-reducing interventions. There is inherent value in answering age-old questions about personality and health, but there is even greater value in the level of mature science that could support successful efforts to prevent disease and improve health.
CONCEPTUAL AND METHODOLOGICAL CONCERNSSeveral key conceptual and methodological issues provide both a general framework for evaluating current evidence regarding the association of personality with subsequent health and an outline of areas of needed research. In each of these issues, clear conceptual models are an essential guide in measurement, design, and analysis.
Conceptualizing and Measuring HealthMany studies examine straightforward outcomes, such as longevity and the onset of specific diseases (e.g., cancer, diabetes) quantified through wellestablished criteria. Associations of personality characteristics with such objective outcomes provide essential evidence in this field, but less objective outcomes often are examined. Widely studied subjective or behavioral outcomes include self-rated health (e.g., physical symptom reports), functional activity levels, and health care utilization. These outcomes predict longevity (Idler & Benyamini, 1997) and are key aspects of comprehensive models of health (Ryff & Singer, 1998). Given current concerns with health care expenditures, utilization of medical services has obvious practical importance.Although important, subjective and behavioral health indicators should not be interpreted as