Nature-nurture

• Define the nature-nurture debate.

  The nature-nurture debate discusses whether nature (biology) or nurture (environment) is more important when it comes to explaining human behaviour.
• Outline the nature perspective in Psychology.

  The nature perspective argues that biology is most important so it is consistent with the biological approach in that it focuses on how biological factors influence a person’s behaviour more than environmental factors.
• Give an example of the nature perspective in Psychology.

  Examples of these biological factors include genes (e.g. how an underactive MAOA gene can lead to offending behaviour), neurochemistry (e.g. how high dopamine activity can lead to schizophrenia) and brain structure/function (e.g. how abnormalities in the worry circuit of the brain can lead to OCD).
• Evaluate the nature perspective in Psychology: supporting evidence. 


  Twin studies have found that MZ twins (who share 100% of their genetics) have a higher concordance rate for many psychological disorders than DZ twins (who share 50% of their genetics). This is a strength because their higher concordance rates can be explained by the fact they share more similar genetics, thus suggesting biology is an important factor in human behaviour.
• Evaluate the nature perspective in Psychology: confounding variables.

  MZ twins may have a higher concordance rate than DZ twins because they are more likely to share similar environmental experiences. This is because MZ twins are always of the same sex (unlike DZ twins) so are more likely to share the same friendship groups, experiences etc. This is a limitation because it could mean that their higher concordance rates for psychological disorders can be explained by environmental factors i.e. nurture rather than nature.
• Outline the nurture perspective in Psychology.


  The nurture perspective argues that environment is most important so it is consistent with the learning approaches (behaviourist and SLT) in that it focuses on how environmental factors influence a person’s behaviour more than biological factors.
• Give an example of the nurture perspective in Psychology.

  Examples of these environmental factors include classical conditioning and operant conditioning (e.g. how phobias are learned through classical conditioning and maintained through operant conditioning) as well as social factors (e.g. how a dysfunctional family environment can lead to schizophrenia).
• Evaluate the nurture perspective in Psychology: supporting evidence. 


  Bandura’s bobo doll study involved children observing an adult role model behaving aggressively or non-aggressively towards a bobo doll. Bandura found that the children who observed the aggressive adult were later observed to behave more aggressively towards the bobo doll than the children who observed the non-aggressive adult. This is a strength because it shows how behaviours such as aggression are learned through social learning, suggesting that environment plays an important role in human behaviour.
• Evaluate the nurture perspective in Psychology: contradictory evidence.


  Bandura also observed that boys behaved more aggressively towards the bobo doll than girls, regardless of whether they observed an aggressive or non-aggressive role model. This is a limitation because these findings could be explained by how boys have higher testosterone levels – a hormone linked to aggressive behaviour. As a result, biology (nature) may have been more important than their environment (nurture).
• Outline the interactionist perspective in Psychology.

  Given that there is evidence to support the importance of both nature and nurture, many psychologists now take an interactionist approach to explaining behaviour. This proposes that nature and nurture are equally as important as one another and interact to control human behaviour (e.g. the original diathesis-stress model of schizophrenia proposed how a genetic vulnerability interacts with an environmental stressor to lead to the development of schizophrenia).
• Evaluate the interactionist approach: supporting evidence. 


  Research has found that when no light is perceived by the retina, the SCN instructs the pineal gland to secrete melatonin, thus inducing sleep. This is a strength because it demonstrates how nature (internal body clocks/endogenous pacemakers) and nurture (external factors/exogenous zeitgebers) interact to regulate human behaviour such as the sleep/wake cycle.
• Evaluate the interactionist approach: nature and nurture do not always interact.


  The two-process model proposes that phobias are learned and maintained through classical and operant conditioning. The biological theory for phobias proposes that some are innate due to our evolutionary past so aim to aid our survival. This is a limitation because it suggests that some phobias may be learned while others may be innate.