Unit 2 2.2 Genetic Theories

Question 1

Twin studie - christiansen

Answer 1

Monozygotic 100% genetically identical twins
Dizygotic NOT 100% identical to each other

3586 twin pairs in Denmark (monozygotic twins and same with dizygotic twins)
Followed them round observing them
Conclusion - that 52% of identical twins (monozygotic) are more likely to that if one twin turns to crime 52% chance that the other on is based on genetics
In Dizygotic there is only 22% chance that the other twin will become a criminal.

Question 2

Adoption studie by mednick et al

Answer 2

Examined 14000 adopted sons in Denmark
Found that sons were more likely to have a criminal record if a birth parent also had a criminal record. 20% chance of being criminal if your parents are.
14.7% chance in adoptive parents.

Question 3

Twin studie strengths

Answer 3

Identical twins are better to study than children who are just siblings as identical twins share the same genotype.

Easily replicated as you can conduct it on more sets of twins.

Question 4

Twin studie weaknesses

Answer 4

Can’t be generalised to the general public as not everyone is a twin so doesn’t apply to them

The environment of what the twolins are in also play apart in why twins may commit crime

52% concordant rate is low as if genes were the only cause of criminality identical twins show 100% concordance rate but studies only show half
(50%)

Question 5

Adoption studies strengths

Answer 5

Adoption studies are better than twin studies as you can separate adopted kids to biological kids environment to see how the environment effects the behaviour of the kids and not base it on genes.

Look at how a person environment show how a person will become

Question 6

Adoption studies weaknesses

Answer 6

It’s a biological studie as its more based on environment as its not based on a experimental study (as it based on observation)

Not always easy to get in touch with kid biological study. It’s unethical as mednik ask personal questions to parents that don’t want to be contacted

Scientists want a more scientific study

Question 7

Jacobs XYY super male syndrome

Answer 7

Abnormality of sex chromosome is another possible genetic cause of criminality.
Chromosomes are made up of DNA and protein