ABSTRACT
Across the past quarter century, the disciplines involved in the study of human development have witnessed extraordinary developments in the theoretical models used to frame the study of ontogenetic change. The breadth of these changes, if not constituting an actual paradigm shift (although I believe that is the case), cer tainly involves quantitative and qualitative changes of unprecedented scope in the range of levels of organization thought to be involved in human development (e.g., Bronfenbrenner, 1979; Elder, Modell &: Parke, 1993; Gottlieb, 1992; Tobach 8c Greenberg, 1984), the por tions of life wherein development is believed to occur (Baltes, 1987), and the system of ideas used to integrate information about the role of multiple levels in life-span development (Ford 8c Lerner, 1992; Sameroff, 1983).
