Men with older brothers more likely to be gay - Having several older brothers increases the likelihood of a man being gay, a finding researchers say adds weight to the idea that there is a biological basis for sexual orientation.
“It’s likely to be a prenatal effect,” said Anthony F. Bogaert of Brock University in St. Catharines, Canada, “This and other studies suggest that there is probably a biological basis for” homosexuality.
From
Popper
