Nature vs. Nurture
The nature versus nurture debate continues. It centers on the contributions of environmental factors and genetic inheritance to human development. Cognitive psychology and behaviourism advocate that the external environment is more influential in human behaviour, mental illness and personality development. So does the sociological perspective. On the contrary, the biomedical model argues genetic inheritance plays the greatest role in human development. It is the psychoanalytic theory and the humanistic branch of psychology that acknowledges the contribution of both (Barkway, 2009, p. 14).
Research carried out across Sweden, Britain and America on 240 octogenarian twins established the heritability of IQ at 62%. So far, this is the most convincing nature evidence. The researchers were able to find a correlation between the IQ of adopted adolescents and their biological parents. However, correlation did not exist between the IQ of adoptive parents and the adopted adolescents (Barkway, 2009, p. 15). Furthermore, in the case of Schizophrenia, heredity influences less than 50% chance of the occurrence of the disorder. Other factors in the environment influence whether the disorder manifests in a person.
It is evident, therefore, that one’s personality and behaviour does not develop without the influence of both the external environment and genetic inheritance. Advancements in the human genome have made it clear that both nurture and nature theories are partly right. Presently, majority of experts agree that development and behaviour are influenced by nurture and nature. Both are interdependent components of personality development that influence human behaviour. They also determine whether an individual develops a mental illness.
Reference list
Barkway, P. (2009). Psychology for health professionals. Sydney; New York: Churchill Livingstone/Elsevier
