Lots of supporting evidence; supports the assumption that genetics are involved in causes of behaviour because when there is a higher proportion of genes shared, the disorder is MORE likely
Correlation between neurotransmitter levels and mental disorders. This means it is only a relationship. Cannot be concluded that neurotransmitter levels cause the behaviour.
Concordance rates in twin studies are never 100%. This suggests that behaviour is not purely genetic. Approach fails to recognise the role of the environment on behaviour.
Lack of validity due to differences in physiology/brain structure. This means findings may not generalise to humans as thought processes are underestimated
Emphasis on environmental factors affecting behaviour. This means the approach views free will as an 'illusion'. Suggests no conscious control over behaviour.
Emphasises environmental impact. Doesn't account for biological factors eg. gender difference. This means it is not a complete explanation for behaviour.