The search for the “gay gene” is rooted in a fraught question: Does homosexuality have a biological basis? The reasons society asks these questions are complex. The answers scientists have uncovered are somewhat less so. As a new PNAS paper published [June 10] shows, there is evidence that certain biological processes are linked with male sexual orientation.
The team, which included University of Toronto Mississauga assistant psychology professor Doug P. VanderLaan, Ph.D., used data on 827 men to link three “biomarkers” to male sexual orientation: fraternal birth order, handedness, and “familiality.”
They looked at the distribution of these biomarkers in their sample of men, finding that while most men fell into a category of “no biomarker,” the rest could be divided into three subgroups, each based on one of the biomarkers. And within each of those subgroups, there was a higher proportion of non-heterosexual men.
For now, says VanderLaan, we can safely take away the idea that “there appear to be distinct biological processes that influence male sexual orientation development, and each of these processes seem to apply to a particular subgroup of men.” These processes, he continues, may also affect gender role expression and personality.
Read full, original post: Male Sexual Orientation May Be Influenced by 3 “Biomarkers,” Say Scientists