Developmental biology of adult and old age: Most of the theories that explain the decline in old age, are based on cellular damage, loss of function, etc … Another branch of biological research says old age from the theory of cumulative wear: the processes of cellular metabolism lead to the production of waste materials in the elderly can not be renewed completely. However, recent studies have uncovered the existence of some substance administered to the old bodies, dissolved waste substances and allows the return to equilibrium. This supports the idea that the degenerative process is not irreversible. In a dialectical interpretation of development, individual psychological development is viewed from an interactionist perspective between biological changes, cultural and social. CRITICAL ANALYSIS OF THE HISTORY OF GERONTOLOGY: After reviewing the literature on quantitative analysis, the vast Most of these studies represent little more than an outpouring of effort needs to be blurred in part by the statistical methodology that supports them. To Riegel, our concepts of research and theory have not progressed beyond the point of view of the nineteenth century.

A mechanistic approach to research causes no rise in knowledge and not help the growth of society. The progress in knowledge and science is always codetermined by non-scientific factors and by the demands of the society in which they thrive. Following Riegel, it is necessary to incorporate new models in the social sciences and particularly in gerontological psychology. This is the research and models to enable us to develop a more rigorous conceptualization.