Everyone is unique and not everyone needs to successfully master each level to acquire an earlier ego skill in a future stage of life. Erik Erikson's theory arises primarily from environmental influence. There are data or analyzes that offer insight into biological factors that might alter stages of psychosocial development. Although the environment has a strong influence on human development, I believe that our genetic makeup can sometimes be enough to overcome previously failed stages. An example would be a person who grew up in a poor environment, only to overcome pain and suffering and succeed in all stages of life. I also like to think of myself as a good candidate for someone who failed in the early stages of their psychosocial development, only to gain previously lost ego skills during later stages of their development.