Twin studies

• Strength

  • Correlation enables researchers to investigate influence of genes - assumes and twins share the same environment - different between the two groups is genetics - Trait is genetic then MZ twins show higher concordance rate than DZ twins - investigate the effect of genetics on behaviour
• Weakness

  • Twin studies may overestimate genetic influence - MZ twins have more similar environments they are treated more similarly - Dz twins tend to be treated less similar - some of the estimated similarity is due to shared environment