This Kleemeier Lecture is dedicated to persuading the reader that the issues of heterogeneity of aging processes, the modifiability of these processes, and choices in constructing alternative futures of aging made possible by this modifiability are logically and historically related in gerontological research and theory. Persistent heterogeneity observed among older adults indicates aging processes are the synergistic products of biological, psychosocial, and cultural factors. Evidence of modifiability promotes consideration of alternative policies regarding the construction of alternative futures for older adults and aging societies.