AO3 Diathesis stress model

Question 1

problems with twin studies

Answer 1

• Lange’s research poorly conducted
• judgements related to which twins were MZ and DZ were based on appearance rather than DNA testing
• may lack validity
• most twins are raised in the same environment = major confounding variable

Question 2

Biological reductionism

Answer 2

• criminality is complex
• explanations that reduce offending to genetic or neural levels may be too simplistic
• crime does tend to run in families but so does emotional instability, mental illness, social deprivation an poverty
• makes it difficult to separate the effects of genes and neural influences from other possible factors
• MZ twins do not show 100% concordance

Question 3

Diathesis stress model offers support to genetic explanation

Answer 3

• Mednick et al
• 13,000 danish adoptees
• researchers defined criminal behaviour as being in possession of at least 1 court conviction
• checks against police records
• neither biological parents had convictions = 13.5% adoptees did
• either biological parent had convictions = 20%
• both parents had convictions = 24.5%
• biological rather than environmental impact so suggests biology has more of an impact