Evaluation

Cards (3)

  • Environment is a confounding variable
    One limitation of the genetic explanation of criminal behaviour is that the environment may act as a confounding variable:
    • Evans and Martin suggest parents, teachers etc. treat MZ twins more similarly than DZ twin
    • Therefore, greater similarity in terms of criminal behaviour may also be due to greater similarity of experiences
  • Support for the DSM
    One strength is support for the diathesis-stress model of offending:
    • Mednick et al. analysed 13000 Danish adoptees and found that when neither set of parents had convictions, 13.5% of adoptees did
    • This rose to 20% when either of the biological parents had criminal convictions, and 24.5% when both sets of parents did
    • Therefore, both genetic inheritance and environmental influence play a role in determining offending behaviour
  • Nature vs nurture
    One strength of adoption studies is that they offer support to the nature vs nurture debate:
    • Adoptees are exposed to different environments than that of their biological parents, so it is easier to separate the effects of nature and nurture than for twin studies
    • However, there may be trauma with being adopted, which can act as a confounding variable
    • Furthermore, adoption after birth means biological contact may have been maintained