Physical and Mental Health and Well-Being

Central to the study of gerontology and influential in its development have been the changes in health that occur at older ages and the implications of these changes for social and medical services, family relationships, and public programs. It has long been recognized that mortality rates increase at older ages, along with functional limitations and chronic diseases. But the level of the underlying rates are far from fixed and there is considerable variation over time and across groups, prompting intensive study of the empiricallevels as well as underlying mechanisms from the standpoint of biology and biodemography (see Wachter and Finch