Male homosexuality and maternal immune responsivity to the Y-linked protein NLGN4Y
Abstract
Gay men have, on average, a greater number of older brothers than do heterosexual men, a well-known finding within sexual science. This finding has been termed the fraternal birth order effect. Strong scientific interest in sexual orientation exists because it is a fundamental human characteristic, and because its origins are often the focal point of considerable social controversy. Our study is a major advance in understanding the origins of sexual orientation in men by providing support for a theorized but previously unexamined biological mechanism—a maternal immune response to a protein important in male fetal brain development—and by beginning to explain one of the most reliable correlates of male homosexuality: older brothers.
- Publication:
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Proceedings of the National Academy of Science
- Pub Date:
- January 2018
- DOI:
- 10.1073/pnas.1705895114
- Bibcode:
- 2018PNAS..115..302B