Psychology - Issues and debates - nature-nurture Cheat Sheet (DRAFT) by Taalithaa

Nature suggests that internal physical factors affect your behaviour such as genes or hormones. Heredity are traits passed down from parents to their offspring through genes. For example Joseph, when conducting twin studies, found that monozy­gotic twins (100% identical genes) were 40% likely to be diagnosed with schizo­phrenia if their twin had the mental disorder as well, however, dizygotic twins (50% identical twins) were only 7% likely to be diagnosed with schizo­phrenia if their twin had also been diagnosed. This shows that nature (genes) has a strong link with schizo­phr­enia. Another example of behaviour being determined by nature is ocd being caused by a damaged caudate nucleus. An individual with ocd hen in the presence of a potential germ hazard will have their orbital frontal cortex send a worry signal to the thalamus causing it to become over excited and cause excessive anxiety. However, in an individual without ocd when in the presence of a potential germ hazard will have their caudate nucleus suppress the worry signal meaning they will not experience excessive anxiety. Therefore this shows that a damaged caudate nucleus which is a natural factor can cause ocd.

Nurture suggests that external factors such as experi­ences will determine your behaviour. For example phobias are explained by Mowrer using the two process model which suggests that external factors such as classical condit­ioning can cause phobias and operant condit­ioning can maintain them. For example, to form a phobia such as arachn­ophobia the individual will go through classical condit­ioning where a spider will be paired with a fearful moment and will cause the two to be associated meaning that each time they are presented with a spider they experience excessive anxiety. The phobia is then maintained by operant condit­ioning as whenever they see a spider and run away this removes the anxiety and acts as a reward therefore causing them to repeat the behaviour. This suggests that phobias are caused by external factors such as experi­ences.

It is important to determine whether behaviour is determined by nature or nurture as it allows us to develop effective treatments to mental health disorders such as depres­sion. if it is due to internal factors such as hormones this should be dealt with using medication however if it is due to experi­ences this should be dealt with methods such as cbt. However the most widely accepted suggestion is the intera­cti­onist approach which suggests that both nature and nurture work together to determine behaviour rather than working in opposi­tion. For example, social learning theory can be seen as taking the intera­cti­onist approach. Bandura suggests that behaviour is determined by observing behaviour and imitating it. (the likelihood of someone imitating a behaviour is increased if they identify with the model or experience vicarious reinfo­rce­ment). This is suggesting that nurture determines our behaviour however bandura acknow­ledged that the urge to aggression may be due to genetics suggesting that what determines aggressive behaviour is an intera­ction of both nature and nurture factors.

Another intera­cti­onist approach to the nature nurture debate is the diathesis stress model which suggests that an individual may have a genetic predis­pos­ition to a mental health disorder such as depression but may only experience the disorder if triggered by a life experience such as a death in the family. This shows that internal factors may not always determine behaviour without enviro­nmental input.

The intera­cti­onist approach suggests that nature and nurture cannot be separated. For example, Donald Hebb suggested that trying to separate the influences of nature and nurture on behaviour is impossible such as trying to determine whether the length or width is more important when finding the area of a rectangle. They both contribute essential factors. There is a genetic disorder called PKU which prevents an amino acid from being metabo­lised resulting in brain damage. However, if it is detected at birth and the child is put on a specific diet they can avoid brain damage. This matters because it shows that enviro­nmental manipu­lation can bypass the genetic disorder showing the importance of the intera­cti­onist approach.

Plomin also took the intera­cti­onist approach and presented the idea of reactive gene enviro­nment intera­ction. The reactive gene-e­nvi­ronment intera­ction suggests that a child who is innately more aggressive may cause external factors such as other people's treatment towards them to be more aggres­sive. Therefore the genetics of the child is determ­ining their enviro­nment. This also ties into the idea of passive influence which suggests that a parent with a genetic mental disorder such as depression may create an unsettled home enviro­nment for the child. The child may then develop a mental disorder due to the enviro­nment passively. This matters because it shows how nature can indirectly determine nurture and suggests an intera­cti­onist explan­ation would be better. Epigen­etics are another example of an intera­ction of how nature and nurture work together to affect behaviour.

Epigen­etics are genes that can be changed by life experi­ences such as a stress diet or exercise. These life experi­ences can turn on or off certain genes. These genes are then passed on to the next genera­tion. For example, Dias and Ressler exposed male lab rats to the smell of acetop­henone and each time they exposed them to the scent that would give them electric shocks. They soon showed a fear response to the scent. However, the rats later had children and grandc­hildren who were not shocked but still showed a fear response to the scent of acetop­henone even though they were not condit­ioned to. This matters because it supports the idea of epigen­etics. Therefore the behaviour was determined by an intera­ction of the external factors of the first rats and the internal factors of the later rats. Therefore this suggests that an intera­cti­onist approach to the debate would be best.

Epigen­etics are genes that can be changed by life experi­ences such as a stress diet or exercise. These life experi­ences can turn on or off certain genes. These genes are then passed on to the next genera­tion. For example, Dias and Ressler exposed male lab rats to the smell of acetop­henone and each time they exposed them to the scent that would give them electric shocks. They soon showed a fear response to the scent. However, the rats later had children and grandc­hildren who were not shocked but still showed a fear response to the scent of acetop­henone even though they were not condit­ioned to. This matters because it supports the idea of epigen­etics. Therefore the behaviour was determined by an intera­ction of the external factors of the first rats and the internal factors of the later rats. Therefore this suggests that an intera­cti­onist approach to the debate would be best.