Concepts of the Life Cycle: Their History, Meanings, and Uses in the Social Sciences

Life cycle is among the most widely used concepts in the social sciences. It may be invoked merely to denote temporality. It may be applied metaphorically or heuristically to initiate an analysis. Or it may comprise the core assumptions of a research program in developmental processes. Strictly defined, life cycle refers to maturational and generational processes in natural populations. Alternative conceptions of life cycle, like life span and life course, do not share the same intrinsic reference to generation or reproduction that transcends the single lifetime of the individual. Still these concepts are often used interchangeably. The history, meanings, and uses of these concepts across anthropology, psychology, economics, and sociology are reviewed. Three areas of modern sociology--individual aging, family life cycle, and organizational life cycle--are examined specifically in their treatment of life-cycle concepts. Finally, the implications of alternative usages for the study of populations as opposed to individuals and for the study of stability as opposed to change are considered.