Erikson redeveloped Freud's theory with a new sociological view so to include a life-span psychosocial dimension and introduced an eight stage model of psychosocial development. Each stage within Erikson's model explains the development of an individual from birth to old age and includes psychosocial issues that may predict difficulties for later stages (Greene,2012). Stage one (trust vs. mistrust), occurs during the first year of life and during this stage the infant is unsure of the world they live in and look to their parents or caregivers for stability. If stability is achieved and a there is a reliability and consistency of care the infant will develop a sense of trust. Stage two (autonomy vs. shame and doubt) occurs between the ages of eighteen months and three years. The child is now developing physically and is starting to assert their independence. Erikson states that it is critical that parents allow their children to explore the limits of their abilities and if that independence is achieved in a supported environment, the child gains confidence, if not the child could feel shame and doubt and feel inadequate and that could ultimately affect the next stage as they enter the age when they start school and have to assert themselves frequently without family (Newman & Newman, 2007). Throughout the eight stages of man, Erikson had stressed that one stage of development builds on the success of previous stages and that each stage is distinguished by particular characteristics which can be demonstrated in Appendix A.
Like Freud, Erikson assumed that a "crisis" occurred at each developmental stage (Kroger, 2004). He believed that each new crisis was a heightened sense of demands that represented a pivotal moment in life when there was an increased vulnerability and heightened potential. This was thrust on the developing individual as a result of changes in social demand that accompanied changes in age (Greene, 2012).