What Does Research with Monozygotic Twins on the Role of Heredity

question 115

Multiple Choice

What does research with monozygotic twins on the role of heredity in mental illness indicate?

• A)If one twin is diagnosed as mentally ill, it is inevitable that the second twin will eventually develop the same mental illness.
• B)There is no greater likelihood of the second twin showing mental illness than there would be in any two nontwin siblings.
• C)The second twin has an increased risk of developing the same disorder, but identical twins are usually discordant with respect to mental illness and behavioural disorders.
• D)Mental illness shows almost no evidence of heritability.