Evaluate twin adoption studies (Heston) (8 marks)

Question 1

GENERALISABILITY

Answer 1

→ Low generalisability
→ Twin studies tend to use volunteer sampling
→ Adopting families and therefore likely to be similar to one another making the research less representative

Question 2

HIGH VALIDITY

Answer 2

→ High Validity
→ The amount their DNA shares is different so their is a natural control over their environmental effects
→ Any difference in concordance rate between Mz and Dz twins is unlikely due to environmental effects

Question 3

LOW VALIDITY

Answer 3

→ Low in validity → may overemphasize the role of genes
→ Mz twins are treated more alike because they share their gender and are identical.
→Higher concordance rates in Mz over Dz twins