IN ORDER TO UNDERSTAND change over time in patterns of individual and family development, social historians have made extensive use of three important analytical constructs: the life stages, the family cycle, and the life course. The life stages such as infancy, childhood, adolescence, adulthood, and old ageare developmental phases, each with its own biological, psychological, and social characteristics, through which individuals pass over the course of their lives. The family cycle (which social anthropologists call the "developmental cycle") refers to the stages through which families go as members age and family size expands and contracts. The life course refers to the passage of individuals through major life cycle transitions, such as leaving home, getting married, and entering and leaving school and the labor force.
Lifestages analysis has focused on the changing definition, demarcation, and social experience of the phases of individual development. It has shown that over the course of American history the definition of the life stages has grown more ,conceptually precise and more completely organized institutionally, and that the transition between stages has become more abrupt and disjunctive.
The familycycle approach has concentrated on changes in the basic phases through which families go from the time they are formed to the time they are dissolved. It has revealed the impact of such important demographic developments as declining fertility rates, increasing life expectancy, prolonged residence of children in their parents home, and the decline in the practice of boarding on the familial experience of individuals.
Lifecourse analysis has explored changes in the timing and sequencing of key life cycle transitions. It has found that since the eighteenth century the timing of major transitions has grown more rigid and uniform, and has increasingly come to reflect individual preferences rather than family needs. Taken together, the lifestages,...