Biological Approach to Abnormality / Psychopathology
This approach suggests that abnormality is caused by physical factors; for example changes in brain structure and function.
The Role of Genetics
Individuals may be more likely to have certain illnesses through inheritance from parents. This is because an abnormal gene (which cause illnesses) may be carried on from parent to child over many generations (although it may not be shown in every generation). When investigating the role of genetics, three types of studies can be used; family studies, twin studies and adoption studies. These can establish concordance rates to test if genetic predisposition could be an explanation of abnormality.
Twin studies are conducted by comparing the differences in concordance rates for identical (MZ) twins and fraternal non-identical (DZ) twins. Holland Et Al. (1988) found a 56% concordance rate for MZ twins (identical) and 5% for DZ twins (non-identical) in anorexia nervosa. This supports the idea that abnormality has a genetic basis, however it cannot be the only cause, or the concordance rate for MZ twins (identical) would be 100%.
Family studies have found that first degree relatives share 50% of their genes, and second degree relatives share 25% of their genes. These studies compare the rates for the disorder in those who are related to already diagnosed people, compared to relatives of people with no illness. Masterson and Davis (1985) found that relatives of schizophrenics were 18 times more likely to be diagnosed with the condition themselves. There is a possibility that some people may be genetically at risk of developing a mental disorder.
To help separate between the nature/nurture sides of the argument, adoption…