Biological explanations- Genetic

• Twin studies

  Gottesman reviewed about 40 twin studies and found that with identical twins 48% concordance rate non-identical twins 17%
• Adoption studies

  if same genetics- despite different backgrounds same likelihood to get disorder
• Weakness

  No study has found 100% concordance rate, schizophrenia can’t be caused by just genes

  Other factors need to be considered e.g biochemical or psychological factors