A03

• limitation- use of twin studies

  • methological issues with twin studies
  • Christiansen et al found concordance rates of 33% for MZ twins but only 12% concordance for non-identical DZ twins. 
  • assume that the only difference between twins is the amount of genetic information they share.
  • however MZ twins are likely to share the same environments may explain why MZ concordance rates are higher. This suggests that causal conclusions about the genetic basis of criminality have incorrectly been reached. 
• limitation- biological reductionism

  • simplifies down to small biological components
  • Although it does appear that criminality runs in families, so do other risk factors associated with criminality e.g. a lack of educational opportunities, economic deprivation
  • Therefore, it is important not to stereotype children from criminal families as ‘criminal’ as this may lead to the realisation of self-fulfilling prophecies.
• strength- scientific methods of investigation used

  • empirical methods producing objective evidence
  • eg raine use of brain scans
  • allows for standardisation of procedures which can be replicated for reliability
  • scientific methods eg lab studies also allow for high levels of control and removal of certain extraneous variables
  • thus increasing the validity of cause and effect relationships