From The L.A. Times:
Last month, Sen. John McCain dropped by “Saturday Night Live,” drawing laughs from his promise, if elected president, to fight expensive federal projects -- such as, he spoofed, a Department of Defense device to "jam gaydar."
That was a joke. But some scientists are, in a way, working on gaydar, the supposed ability to discern whether a person is homosexual by reading subtle cues from their appearance. Just don't refer to it that way. The preferred term is "sexual orientation correlates."
These scientists are searching for innate traits that might not appear to be related to sexual orientation or even to standard clichés. So measuring a subject's shoe size is permissible; asking about ownership of Barbra Streisand albums would be cheating. Some inborn traits might be expected if homosexuality is -- as most scientists believe -- rooted in biology, and they might provide clues about the biological origins of sexual orientation.
Finding and solidifying these links isn't easy. Studies contradict each other, and some promising paths don't pan out. (A link between male homosexuality and finger lengths isn't holding up, and a claim that gays have distinctive fingerprint ridge patterns is largely discredited.) Scientists don't always agree on how to interpret the results, and more progress has been made with regard to men than to women.
http://www.latimes.com/features/health/la-he-sex16-2008jun16,0,5424540.story?track=rss