The extent to which health interventions actually improve people’s lives, and the extent to which interventions may become objects of widespread fear and mistrust, are issues that have recurred many times throughout modern history. A dynamic arises at the conjunction of three formidable forces—local experience, institutional interventions, and scientific research—that is a compound of the fit, both good and bad, between them. Understanding this dynamism requires us not to privilege science, nor intervention programmes, nor local cultures—whether as the source of strengths, or weaknesses, in the collective effort to improve health. The Afterword reviews this dynamic, in two steps. First, it steps back from the conceptual and methodological detail of chapters in this book, giving a general view of the obstacles and challenges that remain. Historical prejudices, continuing limitations of data systems in monitoring migration and the spread of disease, the challenges posed for conventional demographics by climate change, and the longstanding demographic tendency to predefine implications of elementary fertility measurement, provide examples. Second, in the concluding sections, the chapter draws on the many case studies in the book to propose a preliminary typology of blockages that have arisen where there is a mismatch between research methods and the societies and cultures to which methods have been addressed. The anthropological demography of health, in the five-part structure of this book, provides an integrative framework which co-ordinates demography, epidemiology, history, linguistics, and other disciplines within a bottom-up, combined qualitative and quantitative approach to societies and their variation.