E1a1 Biological Explanations For Criminality

Question 1

Measuring biological links to criminality

Answer 1

1. Family studies

2. Blood samples and genes

Question 2

Family studies and links to crime

Answer 2

Comparing family trees of criminals and non criminals. If the relatives of criminals are also criminals, there could be a biological basis for crime. If few relatives are criminals- link is weaker. Some studies show child more likely to be criminal if parents/ grandparents criminals

Question 3

Adoption studies and link to crime

Answer 3

Studies look at relatives, siblings and twins adopted at young age- shared genes, different environment. Taking env. out of picture- can be sure genes are the cause.

Question 4

Mednick (1984)

Answer 4

Studied 14,000 adopted children. Looked at how many had criminal records compared to biological and adoptive parents. Found that kids with criminal records for property theft also had bio. fathers with convictions- though they didn’t raise them
^true even when siblings separated and put in different homes

Question 5

Twin studies and crime link

Answer 5

Identical twins- same genes. If both criminals- suggests very strong genetic link

Question 6

Christiansen (1977)

Answer 6

Studies 3000 pairs of twins in denmark. Findings: if one identical twin was a criminal, the other was as well 52% of the time. This only true 22% of the time with non-identical twins
Link was for property crime (theft etc), not violent crime
^evidence that there is gene link to crime- identical twins link stronger-> all genes the same

Question 7

Argument against family/twin studies and crime

Answer 7

Family members are raised together and treated similarly- their similar criminal behavior can be explained by their upbringing and by observational learning. Also, all figures used in theses studies only based on criminals that have actually been caught/ convicted

Question 8

Chromosome abnormalities and crime link

Answer 8

Blood samples taken from criminals. XYY males found to be more likely to be violent and criminal. Condition not inherited, but still gives genetic reason for criminality. Men with this disorder found to be more aggressive and slower at learning.