Nature vs Nurture Debate

Nature vs Nurture Debate

1. Definitions and Examples

   • Nature - The view that behaviour is the product of innate biological or genetic factors.
     • A example of nature is that Bowlby proposed that children came into the world biologically programmed to form attachments because this will help them to survive. This suggest attachment behaviours are naturally selected and passed on as a result of genetic inheritance (heredity mechanism)
   • Nurture - The view that behaviour is the product of environmental influences.
     • An example of nurture is that behavioural psychologists explain attachment in terms of classical conditioning, where food (UCS) is associated with the mother (NS) and through many repeated pairings the mother becomes a CS who elicits a CR in the child. Therefore, the child forms an attachment based on the pleasure experienced as a result of being fed.
   • Interactionist Approach - This is the view that both nature and nurture work together to shape human behaviour.
     • An example on the interactionist approach is PKU. The genetic disorder PKU is caused by the inheritance of two recessive genes. People with PKU are unable to break down the amino acid phenylalanine which builds up in the blood and brain causing mental retardation. However, if a child with PKU is placed on a low protein diet for the first 12 years, they avoid this potentially serious lifelong disorder.

2. Evaluation points

   • Research suggests that the nature-nurture debate has become a meaningless distinction and there is a growing body of research which higlights the importance of an interactionist approach. Research examining neural plasticity suggests that life experiences (murture) shapes our biology (nature). For example, Maguire investigated the hippocampi volume of London taxi drivers' brains. She found that this region of the brain was larger in taxi drivers compared to non-taxi drivers. Consequently, Maguire concluded that driving a taxi (nuture) actually had an affect on the size of the hippocampi (nature), demonstrating the importance of a interactionist approach and presenting evidence that nurture can affect nature.
   • While twin studies are often used to provide support for the nature argument, nearly all twin studies also highlight the need for an interactionist approach. Nestadt examined previous twin studies in realtion to OCD. He found an average concordance rate of 68% in MZ twins and 31% concordance rate in DZ twins, highlights a significant genetic component. These results do provide evidence of a strong genetic component, as the concordance rate of MZ twins is significantly higher than ta=hat for DZ twins, which suggests that behaviour is partly attributed to nature because MZ twins share 100% of genetic material and DZ twins only share 50%. However, the results also highlight the role of nurture as the concordance rate in not 100%, again highlighting the importance of taking an interactionist approach.
   • In psychopathology, many psychologists argue that both a genetic predisposition and an appropriate environmental trigger are required for a psychological disorder to develop; this is set out in the diathesis-stress model. The diathesis is the biological vulnerability such as being born with a gene that predisposes you to develop a disorder. However, the disorder will only develop if there is an environmental ‘stressor’ to trigger it. Evidence to support the diathesis-stress model comes from the Finnish Adoption Study, which compared 155 adopted children whose biological mothers had schizophrenia, with a matched group of children with no family history of schizophrenia. The researchers also assessed the quality of parenting through questionnaires and interviews. They found that the group with schizophrenic mothers had a 10% rate of schizophrenia, but they also discovered that all of the reported cases of schizophrenia occurred in families rated as ‘disturbed’. When the family environmen