Final answer:
Twin studies are used to examine the impact of genes versus the environment on intelligence. They involve studying identical twins who were raised separately to determine the contributions of genetics and socialization to intelligence.
Step-by-step explanation:
Twin studies are one way researchers attempt to sort out the effects of genes versus the environment on intelligence. By studying identical twins who were raised separately, researchers can examine the degree to which genetics and socialization contribute to intelligence. For example, the Minnesota Study of Twins Reared Apart found higher correlations in IQ scores between identical twins raised apart compared to siblings or fraternal twins raised together.