Adoption studies

• Investigate those who have been raised away from their biological parents.
• Concordance rates for behaviour are compared between adopted children and their adopted parents and adopted children and their biological parents.
• A greater concordance rate for adopted children and their biological parents suggests that there is a genetic influence.
• Key study : crowe (1972)


  50% of adopted children raised away from their biological criminal mother had a criminal record by 18

  in the control group this was only 5%

  this suggests that there is a genetic factor