adoption studies

• Adoption studies compare criminal behaviour of adopted individuals to their biological and adoptive parents
• If adopted individual's criminal behaviour is more similar to biological parents


  Suggests a genetic basis for criminality
• If adopted individual's criminal behaviour is more similar to adoptive parents

  Suggests an environmental basis for criminality
• Mednick et al (1975) found adopted sons with criminal convictions were more likely to have biological parents with criminal convictions
• This supports a genetic explanation for criminality