It's a pattern. Humans have evolved to recognize them. When I hear someone say "Can I ax you a question?", my brain does a pretty good job of lumping them into a labeled box. Everyone does it. Maybe not with the same things, but to deny this is a straight up lie. I'm not ashamed of it, it's human. These are just first impressions though. If I speak with someone I'm open to changing my opinion of them. Happens all the time in one way or another. Sometimes I'm even inwardly embarrassed for having assumed something. But not usually. There's a reason people get sorted in those little boxes at first glance. I don't care to get to know every single acquaintance I come across. It's not practical. Pronouncing it "ax" was probably picked up from listening to parents or peers. Not because they're inherently stupid obviously. But when you hear that, do you really not judge at all? You think that there's a fifty fifty shot at them being smart or dumb? No. And I think that's pretty obvious.