For what it's worth, I also misinterpreted your original query as more specific than the topic of this post: "what prevents you from doing mean things when you don't care" as opposed to "how do you prevent and get out of that state." On the other hand, I wouldn't have thought of the empathy response if I hadn't.

This topic is similar to one of the ones I added to my everyday questions post, although that one is specifically about anger loops and focuses more on the mental, rather than tangible, effects. I'd definitely be interested if you had any ideas about that one.