Twin studies
A) cannot be used to study polygenic traits such as intelligence.
B) are based on the assumption that monozygotic twins are not more similar genetically than dizygotic twins.
C) are based on the assumption that heredity influences a trait if identical twins are more alike than fraternal twins.
D) often underestimate the influence of heredity because identical twins may have more similar environments than fraternal twins.

Question

Quizplus · Accepted Answer

Twin studies are based on the assumption that heredity influences a trait if identical twins are more alike than fraternal twins. This is because identical twins share 100% of their genes, while fraternal twins share only 50% on average. Therefore, any difference in similarity between identical and fraternal twins is likely due to heredity.

Twin Studies