Don't think about it. Of many valid reasons to work to change ones behavior, I don't think this is one of them. All that effort you were spending trying to change something that 1. may not be happening and 2. if it is, is "pretty damn typical human psychology" (It's as old as humanity to find ways to look down on others) and there's not really pragmatic ways to stop that short of a lobotomy. Spend that effort on excelling in what you do. Bust ass and the people who matter will respect you regardless, and it makes it easier to tune out the ones who don't.
Feel free to ignore this advice, I've long since decided to avoid commenting in threads like the overarching, but your original concerns and question made me want to try and contribute at least something marginal :)