Gay twin

Human same-sex sexual attraction has been recorded from the beginning of written history. It remains a controversial topic, but recent theories favor prenatal influences. A paradox is the occurrence of same-sex orientation in twins in that there is.

In a study where scientists looked at the sexual arousal patterns of identical twins with different sexualities—specifically, where one was gay and the other was straight—they found that gay twins demonstrated more genital arousal in response to same-sex images, whereas straight twins demonstrated more arousal in response to opposite-sex.