A03

• What is a limitation of twin studies as genetic evidence?

  Assumption of equal environments
• Why is the 'shared environment assumption' more applicable to MZ twins?

  MZ twins are treated more similarly than DZ twins
• How do higher concordance rates for MZ twins affect twin study conclusions?

  They may indicate similar treatment rather than genetics
• What does the diathesis-stress model suggest about offending behavior?

  • Genetic inheritance plays a role
  • Environmental influences are also significant
  • Interaction between genetics and environment affects behavior
• What was the sample size of the Danish adoptees study by Mednick et al.?

  13,000 adoptees
• What percentage of adoptees had convictions when neither parent had convictions?

  13.5%
• How does the percentage of adoptees with convictions change when biological parents have convictions?

  It rises to 20%
• What percentage of adoptees had convictions when both parents had convictions?

  24.5%
• What does the study by Mednick et al. indicate about the role of genetics and environment in offending?

  Both genetic inheritance and environmental influence are important