Why are some people attracted to persons of a different sex, whereas others are attracted to persons of the same sex? Scientists have been searching for an answer to this question for decades. We are far from having any sort of definitive answer, but a growing body of research suggests that biological factors likely play a big role. In addition, it appears unlikely that sexual orientation can be reduced to a single cause--in other words, there may be a series of different pathways that can lead to homosexuality and bisexuality.

For an overview of the current state of the science on the origins of same-sex attraction, check out this episode of the NPR program On Point. Guests include Drs. Lisa Diamond and Qazi Rahman, two of the world's leading experts on sexual orientation. Have a listen and weigh in with your comments and questions below.