Biological Theories - Genetic Evaluation

Question 1

Twin studies
- Strengths

Answer 1

1. Natural experiment - biological rls between the twins are naturally occurring variables and they share same environment so differences in concordance rate must be genetic
2. Helps detection and treatment of psychological and mental disorders

Question 2

Twin studies
- Weaknesses

Answer 2

1. Early twin studies lacked adequate control and validity because they were based on appearance rather than DNA
2. Twins are not a random sample of the population so findings cannot be representative of society.

Question 3

Adoption
- Strengths

Answer 3

1. Its easy to separate genetic and environmental factors as adoptees are exposed to various different environments
2. Studies suggest there is a definite correlation between adopted children and their biological parents

Question 4

Adoption
- Weaknesses

Answer 4

1. Adoptees are not representative of the society so we cannot generalize these findings
2. Adopted children may have previous trauma which could have caused behavioral differences
3. Age of adoption means some children may have already been influenced by biological parents

Question 5

XYY Theory
- Strengths

Answer 5

1. higher proportion of men in prison with the xyy chromosomes than the standard population which is 1 in 1000
2. Alder et all suggested that violent and aggressive behaviour can be determined by genetics
3. having xyy chromosomes does lead to an increased risk of learning difficulties meaning it can be the same for the other side effects

Question 6

XYY Theory
- Weaknesses

Answer 6

1. studies supporting were conducted in a high security psychiatric setting so there was no control group to compare results to
2. genetic abnormalities are widespread in society so this doesn’t explain aggression
3. original xyy man had average intelligence and no criminal record.