The fact that identical twins have approximately a 50 percent concordance rate for homosexuality was presented as evidence for the possible _________ basis for sexual orientation.

Question

Quizplus · Accepted Answer

The fact that identical twins, who have nearly identical genetic makeup, have a 50 percent concordance rate for homosexuality suggests that there is a significant biological basis for sexual orientation. This is because if sexual orientation was purely environmentally or culturally determined, then the concordance rate for identical twins would be much closer to 100 percent.

The Fact That Identical Twins Have Approximately a 50 Percent