My research focuses on the interface between social class and individual psychological traits related to "healthy aging". The social patterning of health is well understood, and attributed to fundamental social forces producing socioeconomic stratification. The role of the individual in these processes is less well understood, and subject to competing hypotheses with differing policy implications. Some models attributing people's individual traits, as well as the health risk they pose, to social class and other broader societal forces. Support for these models favors health policy based on the concept of social or collective responsibility for the health of persons. Models attributing social gradients in health to personality or cognitive traits point toward health policies based on "personal responsibility". Economic, population health, ethical, and social theory implications differ substantially between these two classes of models.