So my Twitter handle is non-gender-specific, and the picture of a giraffe doesn't mark me out as female either. But I've never hidden that I am of the female persuasion.
So I'm a little stunned when someone who's a Twitter acquaintance, and has been for two years, gets confused when I post a high pitched post-glorious Malaysian grand prix tweet about Seb Vettel that went "Seb Vettel just won the heart of this Ferrari girl. <3" because how was I a woman? And then got even more confused when it turned out that I was only 30. Apparently, without any identifying information, my twitter sounds like that of a 40 year old man!
Which is oddly close to the description of the person that got confused, and I wonder if it's just that when we've not got enough information, we fill in with our own backgrounds.