I see this a lot. Everyone can point to someone else and believe they are superior to them in some way. Here are some examples.
If you're religious then the non-religious are lost sheep. If you're an atheist then the religious people are stubborn anti-science fools.
If you're rich it's because you're smarter than others. If you're poor then those rich people don't know how to do the dirty work.
In politics the other side is often not only wrong, but hypocritical and malicious.
I also think this is the root of racism. I've seen racists in a group, and they are often trashy and poorly educated. Race might seem like a silly thing to feel superior about, but if you're the trashiest person in your community, what else are you going to latch onto?
I just don't know of anyone who thinks they're not as valuable and important as anyone else. When the reality is that's just not true. If you died tomorrow, a few of your closest friends and relatives would mourn for a while and life would go on. But there are people who, if they died tomorrow, would cost hundreds or thousands of people their jobs. So I believe those people are quantifiably more valuable, but there's an inherent mental block that prevents us from readily acknowledging it.