In twin studies, it is most common to
A) assess the behavioral similarity of identical twins compared with the behavioral similarity of non-twin siblings.
B) determine the behavioral similarity of identical twins compared with the behavioral similarity of fraternal twins.
C) to conduct genetic studies of the difference between identical twins in their genetic makeup.
D) to compare adopted fraternal twins with each other.

Question

Quizplus · Accepted Answer

Twin studies aim to explore the influence of genetics and environment on behavioral traits. The most common approach is to compare the behavioral similarity of identical twins (who share 100% of their genetic material) with the behavioral similarity of fraternal twins (who share 50% of their genetic material) as they grow up in the same or different environments. By comparing the concordance of traits between these two groups, researchers can estimate heritability, which is the proportion of differences in a trait that is attributable to genetics. Comparing identical and fraternal twins is the most powerful design to separate genetic and environmental factors in influencing behavior.

In Twin Studies, It Is Most Common to