http://news.yahoo.com/s/ap/20060626/ap_on_he_me/sexual_orientation Men with older brothers more likely to be gay
By RANDOLPH E. SCHMID, Associated Press Writer 1 hour, 42 minutes ago
WASHINGTON - 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.
S. Marc Breedlove of Michigan State University said the finding "absolutely" confirms a physical basis....