Gaydar

Amy: So what do you think of that guy by the bar? Leela: I don't know. Maybe. Bender: Forget it! He's gay. Leela: What? How can you tell? Bender: I just know these things. I've got what they call "gaydar." Leela: There's no such thing. Bender: No? ....Ok, I've got a lock on him. Yep, he's gay! Amy: Are you sure? Bender: Definitely! Unless I'm getting interference from a gay weather balloon.

Gaydar (a portmanteau of "gay" and "radar") is a neologism used to describe a person's alleged intuitive ability to deduce another's sexual orientation.

Scientists have conducted a number of experiments to test if gaydar is more than a myth,          with generally mixed and inconclusive results. Gaydar often relies on stereotypes of LGBT people to assess non-verbal cues such as social behavior, mannerisms, body language, tone of voice, occupation, grooming habits, etc. This is problematic, especially in urban areas where it is more common and acceptable for heterosexual men to exhibit lifestyle habits stereotypical of gay men, and because many LGBT people do not behave in a stereotypically "gay" manner.

Other forms of gaydar are pure woo. For example, in the 1950s, the Royal Canadian Mounted Police used a device jokingly referred to as the "fruit machine," which purported to reveal a person's sexuality by measuring their pupils as they watched pornography. During a campaign to rid the civil service of suspected homosexuals, the fruit machine was used as justification for firing as many as 9,000 government employees. Other similar "gay tests" were used in the US during the era of Joseph McCarthy to disqualify suspected homosexuals from civil service, since they were considered susceptible to and thus a security risk. Roy Cohn must have called in sick that day.