Gaydar (a portmanteau of gay and radar) is a colloquialism referring to the intuitive ability of a person to assess others' sexual orientations as homosexual, bisexual or straight. Gaydar relies on verbal and nonverbal clues and LGBT stereotypes, including a sensitivity to social behaviors and mannerisms like body language, the tone of voice used by a person when speaking, overt rejections of traditional gender roles, a person's occupation, and grooming habits.
Similarly, transdar (a term in use since at least 1996) refers to the ability for trans people to recognize trans people who pass well, by subtle cues such as "the size of the hands and wrists".[1]
However, the assumption of sexual orientation by outward appearance or behavior has been challenged by situations in which masculine gay men do not act in a stereotypically gay fashion, or in which metrosexual men (regardless of sexuality) exhibit a lifestyle, spending habits, and concern for personal appearance stereotypical of fashionable urban gay men.[2][3][4][5] For women, a tomboy might be mistaken for being butch, or a lesbian might act and appear in traditionally feminine ways.
Since at least 2015, media outlets such as Australia's ABC News have called the gaydar "damaging" and possibly "dangerous" due to its perpetuation of harmful stereotypes, its potential to lead to harassment, and its potential to dissuade people from coming out of the closet on their own terms.[6][7][8] Gayety argues that the only way to assess a person's sexuality is based on their open identification and whom they are dating.[9]