Question

explain the rationale for using twins to study intelligence.

Explanation:

Twins, especially identical ones, share a high - degree of genetic similarity. Studying them helps to disentangle the relative contributions of genetics and environment to intelligence. By comparing identical twins (same genes) reared together and apart, and fraternal twins (less genetic similarity) reared together, researchers can estimate heritability of intelligence and understand environmental influences.

Answer:

Twins are used to study intelligence because identical twins share nearly 100% of their genes and fraternal twins share about 50% on average. Comparing them reared in different or similar environments helps separate genetic and environmental factors in determining intelligence.