Genetic Explanation A03 Flashcards
1
Q
Issues with twin evidence - limitation
A
- It is assumed by researchers studying twins that environmental factors are held constant because twins are brought up together and therefore must experience similar environments.
- environments. However, this shared environment assumption may apply much more to MZ twins than DZ twins because MZ twins look identical and people (especially parents) tend to treat them more similarly which, in turn, affects their behaviour.
- Therefore higher concordance rates for Ms in twin studies may simply be because they are treated much more similarly than DZ twins.
2
Q
Support for diathesis stress - strength - Sarnoff mednick (1984)
A
- A study of 13,000 Danish adoptees was conducted by Sarnoff Mednick et al. (1984).
- When neither the biological nor adoptive parents had convictions, the percentage of adoptees that did was 13.5% (which is quite high).
- This figure rose to 20% when either of the biological parents had convictions, and 24.5% when both adoptive and biological parents had convictions.
- This shows that genetic inheritance plays an important role in offending but environmental influence is clearly also important, providing support for the diathesis-stress model of crime.
3
Q
Nature and nurture
A
It is presumed that adoption studies, such as Mednick et al. above, are a good way of separating nature and nurture. if crime has a genetic component, then an adopted child should still xperience the influence of the biological parent despite not living with them.
However, many adoptions take place when children are older, so they spend several years with their biological parents. In addition, many adoptees are encouraged to maintain contact with the biological family so biological parents exert an environmental influence.
