Twin Studies

• These studies show that the closer 2 individuals are genetically , the more likely they are to develop the same behaviours
• Concordance Rate


  Rate of probability that two people with shared genes will develop the same disorder
• Concordance rate for schizophrenia in MZ twins is about 40% and 17% for DZ twins

  Suggests that ' nature ' or genes are a major contribution to the disorder
• High concordance rate in MZ twins compared to DZ twins suggests schizophrenia has a genetic basis

  BUT it is not 100% which we would expect if schizophrenia was purely genetic

  Perhaps environment plays a part too