Individual human development from birth to death is defined as the ontogenesis. The ability of the human psyche to development and to system acquisition of mental and social functions is called evolutionism. The psyche property, causing a gradual loss in the process of ontogenesis of biological, psychological and social functions is defined as involutionism.

Involutivitionism of higher mental functions manifests in their folding in the sequence reverse to the formation. Process of involution is uneven and abrupt. This is caused by their constant interaction with the evolution processes, that are struggling with age-related destruction and disruption and are responsible for the ongoing adaptation, although at a lower ontogenetical level.

In the event of critical psycho traumatic situations, which are related to the impact of jet-psychological, somatoneurological factors, there is a failure of adaptation mechanisms, decompensation develops, the action of the involutive mechanisms increases, which leads to a lower level of social functioning. In this interaction biological and social factors act in their unity and predetermine disadaptation options, while the latter, in their turn, determine intensification of involutive processes.

Because of the interaction of these processes mental aging unevenly affects higher mental functions with the advent of favorable (adamantix) and unfavorable forms, determined by the development of mental disorders and dementia. Favorable aging can manifest itself by specific quantitative somatoneurological and mental changes that do not lead to the loss of adaptation. Under favorable aging life experience, professional skills, biological, social, adaptive resources are preserved, evolutionary development of the older person continues.