theory, and epidemiology to consider variations in human development, giving particular emphasis to the role of hormones in the physiological architecture of the life course. Weiner (1998) offers “notes” toward a comprehensive evolutionary theory that integrates the roles of physical, social, environmental, and psychological factors in the maintenance of good health and the pathogenesis of disease. Keating and Hertzman (1999) assemble a cohesive set of essays that are designed to provide an “integration of knowledge about the determinants of health and human development.” McEwen and Stellar (1993) introduce a multisystem approach to the cumulative physiological toll exacted by adverse behavioral, psychological, social, and environmental influences over the life course. This formulation of cumulative physiological risk is linked to unfolding interactions between genetic and environmental influences over time.
At an even broader level of thinking, E.O. Wilson has adapted and expanded on William Whewell's 1840 notion of consilience (Wilson, 1998, p. 8) as a “jumping together” of knowledge by the linking of facts and factbased theory across disciplines to create a common groundwork of explanation. Wilson emphasized that “a unified system of knowledge is the surest means of identifying the still unexplored domains of reality. It provides a clear map of what is known, and it frames the most productive questions for future inquiry.” Wilson's integration includes not only the full range of scientific disciplines but also the humanities and, as such, represents even more distant horizons for promoting health and well-being.
These perspectives collectively provide conceptual background to the theme of integration that guides this report and our related efforts to characterize pathways to multiple health outcomes. The time for this larger synthesis of scientific disciplines in pursuit of human health has come.
Our task as a committee was one of identifying key elements that comprise an integrated and comprehensive approach to health. When the behavioral and social sciences are emphasized and linked to health, one is automatically led away from a disease-specific emphasis and into a view of multiple pathways to multiple outcomes. For example, smoking is a behavior linked to lung cancer, chronic bronchitis and emphysema, and cardiovascular diseases. Quality of social relationships, in turn, has been linked to cardiovascular diseases, later-life cognitive functioning, and recovery from a variety of illnesses. In both examples, and numerous others documented in this report, there is a need for understanding the pathways underlying these coarse-grained linkages. Moreover, full understanding of pathways requires a long time horizon that includes genetic predispositions and early life antecedents that contribute to later-life health and disease. It