“Explanation,” Philosophy and Theory in Health Inequalities Research: Towards a Critical Realist Approach

The relative lack of attention to philosophy and theory in research on social inequalities in health and its consequences for explanation and methodology has been described in the social epidemiologic literature. Nevertheless, the field of social epidemiology, dominated as it is by the trappings of positivism, is arguably still in need of further development of epistemological frameworks that can adequately incorporate richer explanations of the phenomena we study. Some have advocated for the adoption of a critical realist perspective for the study of social inequalities in health in order to overcome some of the difficulties described above. This chapter uses critical realism as a means to identify some of the epistemological and methodological difficulties inherent in attempts to explain health inequalities (especially the connection between social and biological mechanisms) and offer an “affirmative” approach to health inequalities research based on the insights of ­critical realist philosophy. In both the physical and social sciences, concerns about epistemology and philosophy are routinely left unexamined. This chapter argues that a more explicit engagement with such questions is an important next step in social epidemiology and health inequalities research. The chapter begins with a description of the explanatory problem faced by research on social inequalities in health. This explanatory task is difficult, but it is precisely that difficulty which ­cannot be adequately accommodated by the unacknowledged epistemological underpinnings of social epidemiology. The chapter highlights several key features of the critical realist approach and demonstrates how these can be usefully applied to health inequalities research to solve persistent problems of explanation and ­methodological pluralism. Specifically, the chapter argues that the complexity of the social phenomena implicated in this research demands a more detailed consideration of what is meant by causation, “explanation” and “theory,” and of what the relationship of these concepts should be to empirical research.