nature/nurture

• The nature-nurture debate argues whether a persons development of behaviour is due to nature or nurture. To tackle this argument, researchers usually use an interactionist approach, considering both sides of the argument; both factors are interdependent on one another rather than oppose each other.
• Nature is whereby behaviour is due to innate factors such as genes, neurochemistry and brain structures, with no external/environmental influence. A heritability coefficient can be used to quantify the extent to which a characteristic is due to genetic basis. On the other hand, nurture is the idea that human development is because of external factors that aren’t inside of us, such as people, the world and upbringing.
• An example of the nature debate in terms of mental health disorders such as schizophrenia would be due to genetic vulnerability increasing an individuals risk of developing the condition. For example, in mz twins there is a 40% concordance rate compared to 7% in dz twins. This therefore demonstrates that individuals who are more closely related have a higher chance. However, as it is not an 100% concordsnce rate it suggests the environment also affects development. 
• On the other hand, the nurture debate would suggest environmental factors such as trauma, high expressed emotion and the double bind theory lead t the development of schizophrenia. However, there may be an underlying predisposition, which is why the nature-nurture debate works together.
• +One strength of the nature-nurture debate is constructivism, proposed by plomin. This is the idea that nature affects nurture, through niche picking or niche building. For example, a naturally aggressive child is likely to befriend other aggressive children. This in turn will make them more aggressive due to their environment. Therefore, this idea of constructivism supports the idea that the nature-nurture debate has a multitude of layers in it which affect one anither.
• +Another strength is through research into epigenetics. These are material in each cell that act as switches to turn genes on or off e.g DNA methylation. Life experiences, such as stress or diet can affect our epigenetics and change the way they are passed on down generations. This explains why mz twins have different physical differences, due to different environments such as eating differently which can affect weight etc. therefore this supports how nurture can also directly affect nature (e.g genetics and heredity).
• + use of a diathesis stress model. Tienari et al conducted a study comparing 145 adoptees with schizophrenic mothers to 158 adoptees without the genetic risk. After studying them independently, after 12 years he found 14 went on to develop schizophrenia; 11 were in the high risk group. those without a high risk in a family with high tension + low empathy did not go onto develop the condition, while those with a high risk in same style family did develop schizophrenia - supports the idea that nature-nurture debate works together and diathesis-stress model can be used to support this