Human Longevity, Individual Life Duration, and the Growth of the Oldest-Old Population (International Studies in Population Book 4)

What do we know about human longevity? The scientific community regularly meets to examine and re-examine this question, which persists in intriguing us. Thus in October 1977, the Council of the International Union for the Scientific Study of Population (IUSSP) created a scientific committee on factors affecting mortality and the length of life to allow demographers and actuaries to develop closer links with social and biomedical disciplines. The resulting book, Biological and social aspects of mortality and the length of life, became a reference work for many years. Twenty years later, in 1999, the IUSSP convened a new scientific committee on longevity and health, with the scientific objectives of studying human longevity, the dynamics of health transitions, the emergence and proliferation of centenarians, and demo-epidemiological projections, with the forecast of future health status.This book has resulted from the work of the committee focusing on longevity. Such a book gathering the current knowledge from several perspectives - biology, demography, medicine, sociology - form a crossroads for the diffusion of new ideas and hypotheses.

Old-age survival has considerably improved in the second half of the twentieth century. Life expectancy in wealthy countries has increased, on average, from 65 years in 1950 to 76 years in 2005. The rise was more spectacular in some countries: the life expectancy for Japanese women rose from 62 years to 86 years during the same period. Driven by this longevity extension, the population aged 80 and over in those countries has grown fivefold from 8.5 million in 1950 to 44.5 million in 2005. Why has such a substantial extension of human lifespan occurred? How long can we live? In this book, these fundamental questions are explored by experts from such diverse fields as biology, medicine, epidemiology, demography, sociology, and mathematics: they report on recent cutting-edge studies about essential issues of human longevity such as evolution of lifespan of species, genetics of human longevity, reasons for the recent improvement in survival of the elderly, medical and behavioral causes of deaths among very old people, and social factors of long survival in old age.