Solving the Mystery of 'Gaydar' One More Explanation

The ability to discern sexual orientation may be based on scent—something strongly rooted
in biology.

By Elizabeth Svoboda,  in phycology Today

Everyone knows someone with impeccable "gaydar," the seemingly
 telepathic ability to tell whether someone is gay or straight.
 Research
 is robbing gaydar of its sixth-sense mystique, revealing that some
people literally have the power to sniff out another person's sexual
 orientation—and that that ability is strongly rooted in biology.

When Charles Wysocki, a geneticist at the University of Pennsylvania's Monell
Chemical Senses Center, asked volunteers to sniff underarm sweat from donors
of a variety of genders and sexual orientations, some clear patterns began to
 emerge.
 Gay men strongly preferred the odor of other gay men, lesbians gravitated toward
 the smell of other lesbians, and straight women rated the odor of straight men
 higher than that of gay men. Each group, in short, preferred the smell of their
first-choice mates, indicating a scent-based ability to assess sexual orientation.
Another study confirmed that gay men and lesbians can recognize and identify the
 odor of others who share their sexual preference. This kind of scent-based gayer
enables gays to pinpoint potential partners instantly.