<P> Changes in adulthood have been described by a number of theories and metatheories, which serve as framework for adult development research . </P> <P> Life span development is an overarching framework that considers individual development (ontogeny) from conception to old age . The framework considers the lifelong accumulation of developmental gains and losses, with the relative proportion of gains to losses diminishing over an individual's lifetime . According to this theory, life span development has multiple trajectories (positive, negative, stable) and causes (biological, psychological, social, and cultural). Individual variation is a hallmark of this theory--not all individuals develop and age at the same rate and in the same manner . </P> <P> Erik Erikson developed stages of ego development that extended through childhood, adolescence and adulthood . He was trained in psychoanalysis and was highly influenced by Freud, but unlike Freud, Erikson believed that social interaction is very important to the individual's psychosocial development . His stage theory consists of 8 stages in life from birth to old age, each of which is characterized by a specific developmental task . During each stage, one developmental task is dominant, but may be carried forward into later stages as well . According to Erikson, individuals may experience tension when advancing to new stages of development, and seek to establish equilibrium within each stage . </P> <Ul> <Li> Stage 1--Trust vs. Mistrust (0 to 1.5 yrs) </Li> <Li> Stage 2--Autonomy vs. Shame and Doubt (1.5--3 years) </Li> <Li> Stage 3--Initiative vs. Guilt (3 - 6 yrs) </Li> <Li> Stage 4--Industry vs. Inferiority (6 years to puberty) </Li> <Li> Stage 5--Identity vs. Role Confusion (adolescence) </Li> <Li> Stage 6--Intimacy vs. Isolation (early adulthood) </Li> <Li> Stage 7--Generativity vs. Stagnation (middle adulthood) </Li> <Li> Stage 8--Integrity vs. Despair (late adulthood) </Li> </Ul>

In what stage of adulthood does one more typically use selective optimization with compensation