Which finding is the best evidence that genetics plays an important role in determining intelligence?
A) Identical twins raised apart have more similar IQs than siblings raised together.
B) Adopted children have IQs that are similar to their nonbiological siblings.
C) Siblings raised together have more similar IQs than siblings raised apart.
D) Identical twins raised together have more similar IQs than identical twins raised apart.

Question

Quizplus · Accepted Answer

Identical twins share the same genetic makeup, so the fact that those raised apart still have more similar IQs than siblings (who share less genetic material) raised together strongly suggests that genetics plays a significant role in determining intelligence.

Which Finding Is the Best Evidence That Genetics Plays an Important