Marcus and Julian are identical twins who were adopted by different families shortly after birth. When they reunited at the age of 40, they discovered they had very different temperaments. Marcus is highly anxious and prone to stress, whereas Julian is remarkably calm and resilient under pressure.
Use your knowledge of genotype and phenotype to explain this difference in their temperaments.
48 exam-style questions on AQA A Level Psychology Biological approach. Each one has a worked solution and a mark scheme showing where the marks go.