A BIOLOGICALLY MOTIVATED PARTITIONING OF MORTALITY

For over a century, actuaries and biologists working independently of each other have presented arguments for why total mortality needs to b e partitioned into biologically meaningful subcomponents. These mortal ity partitions tended to overlook genetic diseases that are inherited because the partitions were motivated by a paradigm focused on aging. In this article, we combine and extend the concepts from these discipl ines to develop a conceptual partitioning of total mortality into extr insic and intrinsic causes of death. An extrinsic death is either caus ed or initiated by something that originates outside the body of an in dividual, while an intrinsic death is either caused or initiated by pr ocesses that originate within the body. It is argued that extrinsic mo rtality has been a driving force in determining why we die when we do from intrinsic causes of death. This biologically motivated partitioni ng of mortality provides a useful perspective for researchers interest ed in comparative mortality analyses, the consequences of population a ging, limits to human life expectancy, the progress made by the biomed ical sciences against lethal diseases, and demographic models that pre dict the life expectancy of future populations. (C) 1997 Elsevier Scie nce Inc.