There is a growing recognition that the most powerful determinants of health in modern populations are to be found in social, economic and cultural circumstances. These include economic growth, income distribution, consumption, work organization, unemployment and job insecurity, social and family structure, education and deprivation, and they are all aspects of "social organization". In this work, these issues are examined by British and North American researchers. They bring together an array of evidence from the social sciences, epidemiology and biology. The text starts by examining the strengths and weaknesses of these approaches to improving the population's health. It then considers the timing of major influences on health and questions whether there are special periods of vulnerability early in life or whether circumstances throughout life are equally important. The final section draws out the implications for policy and for links between health and economic performance, emphasising the need for greater investment to combat the low educational standards and high and poor economic performance.