twin studies

• identical twins are monozygotic and share 100% of dna
• fraternal are dyzgotic and share 50% of DNA
• Lange investigated 13 MZ twins and 17 DZ twins
• Found 10 out of 13 MZ twins had both served time in prison
• Only 2 of 17 DZ twins had both served time in prison
• MZ twins have a higher concordance than DZ twins for criminality