Then there’s gender attribution, whereby we look at somebody and say, “that’s a man,” or “that’s a woman.” And this is important because the way we percieve another’s gender affects the way we relate to that person. Gender attribution is the sneaky one. It’s the one we do all the time without thinking about it; kinda like driving a sixteen-wheeler down a crowded highway… without thinking about it.
In this culture, gender attribution, like gender assignment, is phallo-centric. That is, one is male until perceived otherwise. According to a study by Kessler and McKenna, one can extrapolate that it would take the presence of roughly four female cues to outweigh the presence of one male cue: one is assumed male until proven otherwise. That’s one reason why many women today get “sirred” whereas very few men get called “ma’am.”

Kate Bornstein, Gender Outlaw: On Men, Women, and the Rest of US (via queerandpresentdanger)