the influence of genes- twins

• research suggests that behavioural or psychological characteristics can be inherited
• research in this area compares concordance rates of monozygotic twins and dizygotic twins- eg identical twins/mz twins have higher concordance rates of developing schizophrenia
• McGuffin et al (1996) found that if one identical twin has depression, there is a 46% chance that the other twin will also have depression
• research into concordance rates shows that there is a genetic component to illnesses like schizophrenia and depression