Question

The argument that each psychosocial strength has its own special age period of specific importance is the cornerstone of _____ theory of development.

Answer 1

The argument that each psycho social strength has its own special age period of specific importance is the cornerstone of Erickson's theory of development.
Erickson's theory of development emphasizes the socio  cultural determinants of development and presents them as eight stages of psychosocial conflicts. 

Answer 2

The answer is Erikson’s theory of development. Erik Erikson has collaborated with Joan Erikson in this stages of psychosocial development. It is a psychoanalytic theory that has a series of eight stages. An individual, who is healthy growing, must pass through these eight stages. It starts with infancy and ends with late adulthood.