Conceptual Problems in Theoretical Gerontology

CONCEPTUAL PROBLEMS IN THEORETICAL GERONTOLOGY JOSEPH L. ESPOSITO* Current theories of biosenescence, and what has recently come to be called theoretical gerontology, provide an interesting study ofa scientific research tradition in great ferment. Comfort [1, p. 9], for example, observes, "In almost any other important biological field than that of senescence, it is possible to present the main theories historically and to show a steady progression from a large number of speculative ideas to one or two highly probable, main hypotheses. In the case of senescence this cannot profitably be done." I want to consider some of the reasons for this, using along the way some of the work of Laudan and Lakatos on the conditions of scientific progress. I, Conceptual and Methodological Problems Measured by the standards of Lakatos's "research programme," it may be said that there is little tradition of such research on the subject of aging. Historically, such interest has been intermittent and certainly does not reveal the "remarkable continuity" [2, p. 132] required for a research program. The study of biosenescence does not fall into a series of family related theories ever increasing in empirical content. Rather, what we seem to have are many new beginnings as new information in the life sciences became available. Perhaps one reason for this was that it was tacitly accepted that biology studies the "ideal form" ofa species and that, while generation and development were improbable (and so, interesting ) processes to investigate, senescence and degeneration were merely the cessation or absence of these positive influences and comprised no "process" of their own. This view is no longer accepted, however . If it is still not as marvelous as development, aging is now at least regarded as an interesting program in need of a scientific solution. * Editor, Nature and System, P.O. Box 3368, Tucson, Arizona 85722.© 1983 by The University of Chicago. All rights reserved. 003 1-5982/83/2604-0358$01 .00 522 I Joseph L. Esposito · Theoretical Gerontology Laudan's [3] account of research traditions appears more suited to describing the history of the problem of aging. For if the question to be answered is, "What is aging?" we cannot yet even be sure about what we mean by "aging." Richardson [4, p. 752], for example, notes, "The biologist has no operational definition of aging. In point of fact, the central problem of the science of aging is: what is aging?" And Finch [5, p. 30]: "There is no agreement on even the basic characteristics of aging." Only when there is a solution, Laudan holds [3, p. 33], can we be sure there has been a genuine problem, for "it is often unclear whether a seeming problem really is an empirical problem, i.e., whether there is any natural phenomenon there to explain at all." The problem of aging, then, is not unlike the problem, given by Laudan, ofexplaining the cause ofcrystalline growth (p. 19). We must ask whether "growth" is an appropriate description, and, if so, whether the problem is best solved by chemistry, biology, or geology. When we speak of the "aging" of works ofart, we know we are describing a chemical process, and when we speak of the "aging" of cheese, of a biochemical process. Furthermore, we are more or less clear about the way normative assumptions enter the picture : in the former case, a complex form or structure undergoes a change we regard as unfortunate, and so "aging" here is a deteriorative process; while in the latter case, we use the same term to describe a process that is desirable. In theoretical gerontology, on the other hand, "aging" is generally thought to mean the normal, inherent, and progressive deterioration of biological function terminating in death,1 even while it is far from clear what the causes of aging are, in what respect they can be said to be "normal" and "inherent," or whether these changes must be thought of as unfortunate in every theory. Even the distinction between chronoage and bioage [12, p. 311], whereby it becomes possible to say that the president aged more during his term in office than he would have had he remained in private life or that one twin...