phenomena of mental development; the conventional name of the transitional stages from one age period to another; special, relatively short (up to one year) periods of ontogenesis, characterized by sharp psychological changes. Age crises are primarily caused by the destruction of the usual social situation of development and the emergence of another, which is more in line with the new level of psychological development of a person. In contrast to crises of a neurotic or traumatic nature, they relate to the normative processes necessary for normal, progressive personal development. They are associated with systemic qualitative transformations in the sphere of social relations, activity and consciousness. In external behavior, age crises in a child are found as disobedience, stubbornness, negativism, in adolescence – various forms of deviant behavior. In time, they are localized on the borders of stable ages and manifest themselves as a neonatal crisis (up to 1 month), a crisis of one year, a crisis of 3 years, a crisis of 7 years, an adolescent crisis (11-12 years) and a youth crisis. In adulthood, two crisis periods are distinguished: the midlife crisis (30-35 years) and the pre-retirement crisis (between 50 and 60 years), including the climacteric period. Old age (60 – 74 years) and senile age (75 – 89 years) are also characterized by changes in personality and mental activity.