This project proposes to investigate the living conditions of the aged population in Switzerland and to address the diversity of these conditions using an interdisciplinary approach. The study will rely on a survey that will be conducted in 2010. For two French-speaking cantons, the data collected will be confronted to the findings of previous surveys conducted in 1979 and 1994/95, with the aim of estimating changes and continuity in the living conditions.Aging is a major challenge in all industrialized countries. Indeed, over the last century, the proportion of people aged 80 has multiplied by eight! Furthermore, in recent decades, the expectation of life without major illness has risen faster than life expectancy, while the prevalence of dependency decreased among the elderly. A substantial number of positive changes occurred from 1979 to 1994/95. However, nothing ensures that similar trends are persisting. Further, the characteristics of the aged population in 2010 cannot be satisfactorily predicted on the basis of previous data. Indeed, the structure of the aged population drastically changed. More importantly, new generations carrying their own their specificities will soon reach the age of retirement and old age. Provided these various changes, our project will address two major issues simultaneously: heterogeneity among the elderly, i.e. inequalities, and sustainability of the previous positive trends in terms of social participation, health, and longevity.Our theoretical approach will be centered on the concept of resources, as conceived in the theory of lifespan human development and further enriched by sociologists within the life course paradigm. Globally, we consider how resources are built through individual lives embedded in family trajectories and socioeconomic, cultural and political contexts. Thus, we will first estimate how health, family, residency, and occupational lifelong trajectories have constructed the pool of resources available to aged individuals. We further intend to assess the diversity of these resources and the way they are managed by individuals to best maintain an active life, high levels of well-being, autonomy, and health. We will also consider how, in the current experiences of aging, available individual resources interact with accessible sociostructural resources. Such a resource-based, interdisciplinary approach will provide a powerful tool with which to identify the most relevant predictors of well-being, in the past and the present, as well as the levers on which individual action and social policies can push to predict losses and/or promote successful aging processes.