Firstly, the Gottesman and Shields study, which supports the genetic approach, can be seen as less generalisable due to its limited sample and as the participants may not be reliable since they could be separated enough for them to not learn behaviours of other family members. Also, there is no evidence suggesting a 100% concordance rate, thus there must be some environmental factor involved. Hence, evaluating schizophrenia ignoring the environmental factors can be seen as reductionist and deterministic. Moreover, there is some confusion as to whether one or many genes are responsible for predisposing a person to schizophrenia. However, as the genetic approach adopts technological explanations such as using brain scan or genome, its explanation can be seen as more scientific than other approaches such as the cognitive explanation which focuses on the thinking processes which are quite subjective and difficult to be treated.
The dopamine hypothesis can be supported by evidence. Amphetamines increase the amount of dopamine and large doses of amphetamine given to people with no history of psychological disorder often produce behaviour which is very similar to paranoid schizophrenia (Sz) whereas small doses given to