One theory: Validation. Let's say a person is miserable in his current circumstances. Let's say the only thing that brings him pleasure is to try to denigrate and tear down other people, possibly because it makes him feel bigger than he is. It gives him a smug sense of superiority. He colors his surroundings with ugliness so that he appears pure and just.
Another theory: Envy. This person can't tolerate anyone having more than he has. He can't stand the idea that someone, let's say a former peer, friend, sibling - can move up and away from him, and do all the things he 's too afraid to do, like buying a new car, or a new refrigerator, or even a new cell phone. He's so afraid of change, that he cannot tolerate anyone who was once in his sphere of influence going ahead and living life. It infuriates him, especially when the person no longer has need of him.
Theory #3: Narcissism. The person cannot fathom a world that doesn't revolve around him, so he looks for ways to draw others into his rings of hell.
Theory #4: Justification of past deeds. He needs to find a reason to hate others, in particular those who might have been in his circle at some point, because he consistently fails in his relationships. It can't be his fault - it has to be everyone else's fault.
I'd like to feel sorry for such people, but they make it so hard. I guess I'll just have to continue to live my life exactly the way I want, and enjoy my relationships with friends and family, and thrive in the knowledge that I can move on, and leave the past behind.
