Okay, I have some inside info on this. I have deformed hands, and it pisses me off every day. What your brain will typically do in this situation is re-adjust.

So you, yourself, will recognize that you are at a severe disadvantage in the world and life is not going to be easy. In response, you can either stay angry or realize that this is how things are and you should adjust your lifestyle accordingly. This life is easier, but disappointing.

So, if you choose to stay angry, you can maintain this weird energy that will allow you to achieve great things. I think it's because you really want something and you become this larger-than-life person, a type that can really only be compared to story characters - as in, a one-dimensional symbolic human who really wants to be something greater than the person they are, simply because they see that they are, effectively, nothing.

It's an odd life, but not the oddest. I've lived in both, and I remember being much happier when I had accepted my fate, but I tasted something better at some point, something that tasted like love, but was maybe something sweeter that I just wasn't ever meant to to taste, because I could never really have it.

It was the promise of riches and fame and the universal love that comes with it - but the obvious cost would be, that, as someone who had rejected acceptance of themselves, you cannot receive love. You can see it, touch it, smell it, but the real feeling of love, that secure, full feeling fight in your heart, it will never be there, because, in this state of mind, you cannot feel anything.

AND SO, when you can't feel anything, you'll just say anything to anybody because you don't really know the difference.

TLDR - Deformed people are sometimes assholes because it's difficult to maintain confidence without disconnecting themselves from reality, which includes the social veneer a lot of us rely upon.