•Biological explanations emphasise the role of inherited factors and dysfunction of brain activity in the development of schizophrenia.•Most modern psychologists believe that schizophrenia is at least partly biological.
•There are three main biological explanations:–Genetics–The dopamine hypothesis (role of neurotransmitters)–Neural correlates
Explanation 1: genetics
•These are the results of Gottesman’s (1991) large-scale family study.•There is considerable evidence that schizophrenia runs in families and is in part genetic (inherited as genes are transmitted from parent to child).•Gottesman (1991) conducted a large-scale family and found much higher concordance rates in MZ twins (48%) in comparison to DZ twins (17%).
Explanation 1: Genetics
•Schizophrenia is thought to be polygenic (it requires a number of different factors to work in combination) and so different combinations of genes can lead to the condition. Research suggests that there are 108 genetic variations associated with increased risk of schizophrenia.
Measurements of the structure or function of the brain that occur in conjunction with (correlate with) the characteristic symptoms of schizophrenia, and so may be implicated in the origins of schizophrenia
•The ventral striatum is thought to be involved in the anticipation of reward.•Avolition involves the loss of motivation.•Juckel et al. (2006) found a negative correlation between activity levels in the ventral striatum and the severity of overall negative symptoms.•Therefore, activity in the ventral striatum is a neural correlate of the negative symptoms of schizophrenia.