Different approaches to treatment of age-related sensitivity, analyzing models that explain the phenomenon and suggesting the author's own model of the biosocial balance of age-related sensitivity are offered. Age-related sensitivity is treated as a period of balance between biological and social factors which affects the child's ontogenesis and creates favorable conditions for the development of certain psychological functions. On the basis of a general developmental approach the author argues a two-phase character of age-related sensitivity: the first phase is frontal progress of functions in the process of maturation, the second phase is determined by social and personality factors.