Well...I'm no expert with regard to this. However taking pleasure in other people's misfortune is a basic human emotion linked, I believe, to those of envy & jealousy. There's no specific word in the English language for it that I know of. However there is one in German. It is: "Schadenfreude"... "pleasure derived by someone from another person's misfortune." Here's a link to a Wikipedia article that will tell you all about it:

Schadenfreude - Wikipedia

And then here are links to 2 articles, from Psych Central's archives, on the subject:

Podcast: What is Schadenfreude?

Pleasure from Someone Else's Pain

Thanks for asking!