Take away deliberate cultural cues, and I suppose “gaydar” ceases to exist. I wrote a story once about having breakfast at a diner several days a week and not realizing the young man who served me was gay. Until he told me.
But he knew I was, because as a gay man soaked in American gay culture, I deliberately take on certain mannerisms, vocabulary, and ways of being that broadcast my sexual orientation. I’m not over-the-top effeminate or otherwise flaming about my orientation, but I believe my whole presentation adds up to a statement.
My presentation is no longer conscious behavior, though when I was young I suppose it probably was. And I suppose when people cue in on it as, frankly, I expect them to, they perceive the message they receive as being part of their “gaydar.”