>>5 This.
You probably really lack compassion.
This could change after you made a bad experience yourself.
I was kinda the same some years ago, often laughing when hearing bad news, although I didn't actually think they were funny. I simply didn't know how to react instead.
I even remember myself bursting into laughter after my best friend committed suicide.
Still, if you're spactating like it's a show or even pulling the strings, viewing others like pawns in you game, you're definitely suffering from the Izaya-syndrome and this can't be cured. Sorry, man.