Why do some people derive pleasure from misfortune of others?

People have that selfish nature at some points...
It is a bit weird to see people talking about the misfortunes of others and them crossing the borderline. I do experience hearing and seeing people being so interested of the bad thing that has happened to a neighbor or a friend, in Filipino "pagchichismisan".
That attitude seems to be a part of our culture. It serves as the recreation of those people who have nothing to do at all. I find it really irritating to see such things. Why can't those people realize that the mere fact that they were talking about someone else bad experience is like adding more problem to that person?
I guess, we just have to respect personal lives and we should not make fun of others' misfortune.
We have to remember that we all have our own misfortunes to accept,and before intervening to others, let us first resolve our own and who knows? Maybe you will be able to help someone else
after...