The identical twin of a gay man has a 50% chance of being gay,but the fraternal twin of a gay man has only a 15% chance of being gay.This phenomenon suggests that:
A)genetic factors completely determine sexual orientation in men.
B)environmental factors completely determine sexual orientation in men.
C)genetic factors play a minor role in influencing sexual orientation in men.
D)genetic factors play a large role in influencing sexual orientation in men.

Question

Quizplus · Accepted Answer

The fact that identical twins have a 50% chance of being gay while fraternal twins have only a 15% chance suggests that genetics play a significant role in influencing sexual orientation in men. However, the fact that the percentage is not 100% for identical twins indicates that environmental factors may also play a role. Therefore, the best choice is D, which acknowledges the importance of genetics while allowing for some influence from environmental factors.

The Identical Twin of a Gay Man Has a 50