Ananiev specified the two-phase nature of human development during the life span: «In the first phase, general, frontal progress of functions takes place in the course of growth and in the earliest evolutionary changes of maturity» (Ananiev, 1977, p. 201). The laws of ontogenesis play the key role in this period. The second phase differs drastically from the first; it lasts from the onset of maturity to the end of life. This second phase begins at the highest level of functional developments of the first phase and superimposes it. So the peak of the functional development is reached at later stages of maturity, while «the optimum of specialized functions may coincide with the imminent involution of the general characteristics of the same functions» (Ananiev, 1977, p.202). The universal generic program of human development loses the supremacy in adulthood; to be more precise, the development in adulthood is secured by the active forces within the human psyche that counteract the inevitable ageing: «At the second phase of the functions' evolution, their specialisation …occurs» (Ananiev, 1977, p.202).

Ananiev points out a divergent type and a convergent type of aging. The convergent type is characterized by total decrease of functions with ageing, which happens when the psyche's operational and motivational mechanisms are not duly established in the course of life-span development. In the case of the divergent type of ageing, operational and motivational mechanisms provide stability of psycho-physiological functions and even of their progress, which is manifested by optima of certain functions in old age, beyond the limits of biological growth. In the case of the divergent type of aging a total decrease of functions is opposed by active dynamical brain centers resisting decrepitude.

The Ananiev Model of Human Life-Span Development (the "Individuality concept")

Individualization, the increase of individual singularity, is the main effect of human development and its indicator for Ananiev. Ananiev considers individualization as the most important pattern of human ontogenetic development: "Human life journey (biography) influences ontogenetic evolution via the more and more increasing individualization of this evolution" (Ananiev, 1977, p. 165). But "Individuality" is not only individual differences. It is a holistic structure, essentially individual by nature, which emerges in the course of human life activities, bringing to harmony human tendencies and potentials. It turns to be the cause and the result of the integration of natural and cultural development.