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Fascinating Facts the World Knows Thanks to Twin Studies
Numerous twin studies have been conducted in an attempt to clear the importance of genes in sexual orientation. Shutterstock

1. Through recent twin studies, researchers have been able to conclude that sexual orientation is genetically influenced.

Some people claim that sexual orientation is a choice or that being gay is a conscious decision individuals make. To determine the role of genetics, if any, in sexual orientation, researchers compared identical twins to fraternal twins. The 2001 review concluded that almost all identical twins were increasingly more likely to share a sexual orientation. That means that they are both either gay or straight compared to fraternal twins, who are genetically less close. These findings suggest that genes do play a factor in a person’s sexual orientation

Other studies have indicated that biological effects, including hormone exposure in the womb, contribute to shaping sexual orientation. These studies support that the differences in the central nervous system exist between heterosexual and homosexual individuals and that the differences are possibly related to early factors in brain development. There are also findings of physiological differences such as different inner ear shapes between homosexual and heterosexual women that contribute to the idea that biological effects play a role. These studies have been able to debunk the myth that sexual orientation is merely a choice. Instead, it relies heavily on genetic factors.