Friendship offers social and psychological benefits across the lifespan and has different values at different stages of life. Friendship in its broadest sense can be considered a connection between human beings alleviating the isolation of the individual human psyche. Friendship develops across the life cycle and changes as the nature of human psychology and social interactions changes. There are different ways of viewing the life cycle, one way being to see it extending through a series of stages covering infancy, pre-school, early adolescence, adolescence, early adulthood, middle adulthood, and late adulthood. Friendship is important at each of these stages and provides specific comfort and needed interpersonal connections for each individual.
The stages can be framed in different ways and have been by different theorists, and one of the more interesting is that of Erik Erikson because he also links each stage with life conflicts which help identify both the stage and the "problem" to be overcome as part of human development. Erikson's approach is a psychosocial theory of development which describes a series of eight stages in the development of the individual throughout life--Erikson divides the life cycle somewhat differently to get eight stages. This is based on the interaction of biological, psychological, and social processes, and it is the interaction of these processes that accounts for the "psycho" (inner) "social" (external) character of development. The stages are described by Erikson as psychosocial "crises," and the reason for this is that they are intended to represent periods when the individual is particularly sensitive or vulnerable to certain developmental issues. Each of the crisis stages is described by Erikson in terms of its positive outcome or strength "versus" its negative outcome or weakness, and the relative degree to which the resolution of each crisis can be considered favorable or unfavorable ...