AO3

• What is the issue with suing twin studies as genetic evidence?

  The shared environment assumption may apply much more to monozygotic twins than dizygotic twins since people tend to treat them more similarly which in turn, affects their behaviour. Higher concordance in MZ twins may simply because they are treated more similarly
• Who found support for the diathesis-stress model of offending?

  Mednick et al.
• What did Mednick et al. do?

  Studied 13,000 Danish adoptees. When neither biological nor adoptive parents had conviction, the percentage of adoptees that did was 13.5 %. This figure rose to 20 % when either of the biolgocial parents had convictions and 24.5 % when both adoptive and biological parents had convictions
• it is presumed that adoption studies, such as Mednick et al above, are a good way of separating nature and nurture.

  If crime has a genetic component, then an adopted child should still experience the influence of the biological parent despite not living with them. However, many adoptions take place when children are older, so they spend several years with their biological parents. In addition, many adoptees are encouraged to maintain contact with the biological family so biological parents exert an environmental influence
• Who found support for the link between crime and the frontal lobe?

  Kandel and Freed
• What did Kandel and Freed do?

  People with frontal lobe damage tended to show impulsive behaviour, emotional instability and an inability to learn from their mistakes. The frontal lobe is associated with planning behaviour
• One limitation is the link between neural differences and APD may be complex

  Other factors may contribute to APD and ultimately to offending. Farrington et al. studied a group of men who scored high on psychopathy. These individuals had experienced various risk factors during childhood, such as being raised by a convicted parent and being physically neglected. It could be that these early childhood experiences caused APD and also some of the neural differences associated with it, such as reduced activity in the frontal lobe due to trauma according to Rauch et al.
• Understanding the effects of serotonin could lead lead to treatment for criminals in prisoners. E.g. diets to enhance production. Stop use of artificial sweeteners which prevents serotonin production