Genetic AO3

• What did Brunner et al., (1993) find?

  28 males in a Dutch family involved in violent crimes, all having abnormally low levels of MAOA and a defect on their X chromosome was identified
• What does Brunner et al., (1993) support?

  The role of the MAOA-L candidate gene in aggression
• Why is advantageous the role of the MAOA-L gene has been support in aggression?

  Support the core claim that aggressive may have a genetic basis; crediting the nature side of the debate, suggesting that aggression may result from an inherited gene rather than a characteristic developed from environmental factors
• Outline Mobley (1981)


  Defended himself by stating he had a genetic disposition to kill due to his family having a history of aggression after the murder of a pizza shop murder
• How is Mobley (1981) a limitation of genetic explanations to aggression?

  Removes personal responsibility from crimes committed; despite genetics playing a role in governing behaviour, not all those possessing the gene commit violent crime
• What implications might Mobley (1981) have?

  Social implications on policy and the criminal justice system
• What are the issues with twin studies?

  Difficult to determine whether high concordance rates in MZ and DZ twins is due to shared genetics or shared environment
• Why is it problematic that the concordnce rate cannot be distinguished from genetics or environment?

  Inflation of genetic influence of behaviour like aggression may make it difficult to draw concrete conclusions about the exact influence that genetics have; difficult to predict and control behaviour
• Why is it a limitation that recent research into genetic explanations of aggression suggest a genotype-environment interaction?

  The MAOA-L gene may require an environmental stressor to activate aggressive behaviour from adverse childhood experiences, i.e. abuse
• What did Caspi et al., (2002) find?

  That those with the MAOA-L gene variant are more likely to grow up to be aggressive but only if they were maltreated as children
• What is genotype-environment interaction consistent with?

  Stress-diathesis model, proposing that certain characteristics are triggered by traumatic events; biological explanations alone are too narrow in explaining the onsent of aggressive behaviours, reducing the credibility of the explanation