Twins - antisocial behaviour

why do we use twins

• twins can be used to look at correlations between genetic inheritance and behaviour. to get a better look at the nature nurture debate.

• specifically whether anti social behaviour can be attributed to genetics

Monozygotic Twins (MZ):  

• Identical Twins

• exact same DNA; from one fertilized egg

Dizygotic Twins (DZ): 

• Fraternal Twins 

• similar DNA + same environment

• formed from two separate fertilized eggs

Grove et al - observation Aim

To investigate the extent to which anti-social behavior can be attributed to genetics​

Grove et al - procedure

• Twin/Adoption Study ​

  Sample: 

• 32 sets of monozygotic (MZ) twins who were separated at birth - these were further adopted into different families​.

• method: Interviews, tests, and questionnaires.

Grove et al - results

• Heritability of anti-social behaviour: in Adults: 28% in Children: 41%

• The study found a substantial genetic component to antisocial behavior, with a correlation of 0.41 for childhood conduct disorders and 0.28 for adult antisocial behaviors among monozygotic twins

• There is evidence that suggest that as people get older the environment might be more of a factor than genetics itself.