Influence of Sibling Birth Order on Identity and Sexuality

Exploring the Fraternal Birth Order Effect

National Siblings Day brings attention to interesting aspects of sibling relationships. Guest host Selena Simmons-Duffin delves into a unique topic: how the number of older brothers a person has could affect their sexuality. Scientific investigations into sexuality have often been contentious, especially regarding queer communities. Although much early research has been overturned, the ‘fraternal birth order effect’ remains significant.

This effect suggests that a person’s chance of being gay rises with each additional older brother. This phenomenon has been recognized in various regions, including Turkey, North America, Brazil, and the Netherlands. Selena Simmons-Duffin examines this specific detail, discussing its implications and limitations concerning sexuality.

Scientific Pursuits in Sibling Research

Sibling research attracts interest because relationships between siblings influence personal identity development. NPR’s Science of Siblings series offers informative stories, inviting listeners to explore related topics. Readers eager to learn more can reach out to NPR with inquiries about sibling science.

Listen to NPR’s Short Wave on Spotify, Apple Podcasts, and Google Podcasts for more episodes. Support NPR’s work by joining Short Wave+ at plus.npr.org/shortwave, providing sponsor-free listening experiences.

Production Credits

This episode was crafted by Rachel Carlson, with editorial input from Rebecca Ramirez. Brit Hanson ensured the accuracy of the information, and Maggie Luthar handled the audio engineering.

Additional narratives from the Science of Siblings series cover diverse sibling interactions. These stories include insight into National Sibling Day’s heartfelt origins and how prenatal exposure to a brother’s hormones might impact a sister’s life. The series also explores how identical twins with autism experience contrasting life journeys.