I think you mean subconsciously read gender, but it’s an amazing point, which I just raised in a safe zone training I recently attended. Both gender recognition and the pronoun usage happen at a subconscious level. Which is to say, most of us aren’t even aware of the mental processes we use to assign a gender or a pronoun…we just do it automatically, at a subconscious level…and the only time we will stop, is if we really can’t tell which gender someone is.
But suppose someone really looks female, completely they have breasts, hips, more body fat, all the things the brain subconsciously categorizes as female; but they insist, my name is Aaron, and use the pronouns he, him, his for me. Honestly? That is going to throw most human brains for quite a loop. Primarily because we live in a society that is heavily, heavily invested in us all throwing people into boxes labeled male or female, and keeps no people inside those boxes. And I bet most western societies, if not all societies are like this.
One really cool thing that I find about the trans movement, is the rejection of those very binary gender boxes. But while it’s really cool intellectually, practically it’s often difficult to interact with trans people correctly because subconsciously we’re throwing them into the wrong box. In order not to do this, we would have to train our brains to not make automatic assumptions about gender — and that’s a nearly impossible task. It’s one of the very first things we learn to do in life when we learn the difference between a mommy and a daddy.