Apparently, the nature-nurture issue also exists in the epigenetic principle. As seen from the above explanation of the epigenetic development that "development throughout life is influenced by an underlying genetic plan common to all members of our species... operating within the social context" (Rybash, Roodin & Santrock, 1991), the nature controls when the stage emerges and the nurture side controls how the crisis in each stage is resolved, since “an underlying genetic plan” mainly involves maturational factors while “the social context” primarily involves environmental factors.
Erik Erikson, a neo-Freudian psychologist who termed this species wide, biological phenomenon the “epigenetic principle” or epigenesis, postulated in his epigenetic theory of social development that individuals pass through eight qualitatively different stages, each one associated with a crisis that must be satisfactorily resolved to developing trust, autonomy, and initiative, etc., whereas unhealthy or unsatisfactory resolutions result in mistrust, shame and doubt, and guilt, etc., which may leave a person psychologically troubled and less able to cope effectively with future situations.
According to Piaget’s theory, cognitive development also adheres to the epigenetic principle suggested by Erik Erikson. Piaget proposed that cognitive development proceeds through a series of distinct stages that emerge in the same predetermined order in all children’s thinking. Children’s knowledge and mental strategies develop at different ages in different areas. For example, in the first three or four months, children achieve the maturation of sense, indicating the absence of the limit of the newborn’s vision and hearing. After that, children develop the ability of mental representation, which for sure is based on the maturation of the sensory abilities. Undoubtedly, they must first see the objects to form the mental representation of the objects. Although the success of building the mental representation abilities is based on the success of maturation of senses, the emergence of the stage for developing mental representation has nothing to do with the success of maturation of senses. If an infant fails to achieve the maturation of senses during the first 3 to 4 months, the child’s mental representation abilities will still develop, when the child reaches around one year old, but unhealthily.
One of the characteristics of epigenetic development is that for each stage, an individual develops a new, different ability or “functional whole” as Freud termed. It is not adding new processes to previous abilities. As in cognitive development, the following stage of the children’s mental representation ability development is not for adding more models or schemas to the representation ability, but for developing the brand-new symbolic thought. While stepping onto the next stage of development, the previous development, whether successful or not, ceases because the ability has been perfectly developed and the optimal time of the development has passed. The generation gap will be a good example to that, as most experience.
It is very important for those changes to be epigenetic rather than “just adding new processes to previous abilities” (Jeff Haig, 2003). Growing up, we need to develop various abilities that are not very much related. Just adding new processes to previous abilities will not create most of the new abilities needed. As in the first stage trust vs. mistrust of Erikson’s eight stages of psychosocial development, adding more processes to the children’s learning of trust or mistrust will not necessarily result in the second stage of autonomy vs. shame and doubt in which children excise will. Furthermore, in children’s cognitive development, obviously, the first stage of maturation of senses will not be developed into voluntary movement that requires the growth of child’s strength. Another advantage of the epigenetic change is that if one of the stages’ development is thwarted, the development of the other stages will not be affected and still emerge at the right time. If the growth is continuous and incremental, anything blocking the whole process of development may result in the stop of all the development. Nothing is more serious than that. I think that epigenetic development might be a natural selection according to Darwin’s evolutionary theory.
We need a quick development of a certain ability to survive. Abilities growing little by little may expose our children to risks, since they have the incentive to explore the world while their exploring abilities are not yet mature enough.
References
Bernstein, Douglas A., Penner, Louis A., Clarke-Stewart, Alison, Roy, Edward J, (2003). Psychology (Sixth Edition). New York: Houghton Mifflin Company
Erikson, E.H. (1963). Childhood and Society. New York: W.W. Norton & Company Inc.
Erikson, E.H. (1968) Identity Youth and Crisis. New York: Faber.
Erikson, E.H. (1980). Identity and the Life Cycle. New York: W.W. Norton & Company.
Erikson, E.H. (1982). The Life Cycle Completed. New York: W.W. Norton & Company.
