What evidence suggests a hereditary basis for extraversion?

Question

What evidence suggests a hereditary basis for extraversion?​

Quizplus · Accepted Answer

The fact that monozygotic twins are more similar in extraversion than dizygotic twins suggests that there is a hereditary basis for extraversion. Since monozygotic twins share 100% of their genes while dizygotic twins share only 50%, this suggests that genetic factors play a significant role in determining extraversion. Twins resembling each other more closely than siblings (choice A) and adopted children resembling their adopting parents in extraversion (choice D) could also suggest a hereditary basis, but these pieces of evidence are not as strong as the evidence provided by twin studies. Choice C, that dizygotic twins are more similar in extraversion than monozygotic twins, would actually suggest the opposite: that there is less genetic influence on extraversion.

What Evidence Suggests a Hereditary Basis for Extraversion?​

What Evidence Suggests a Hereditary Basis for Extraversion?