I hadn't thought of it in those terms before (and also hadn't thought of H/C before, although my Gen leanings might explain my complete lack of interest in the genre...)

I think I'd want to turn it around to 'how the world acts on the characters', mostly because the other way round implies that Gen *has* to have a plot, which I don't think it does. Most character studies, I would divide as Gen, but a lot of them don't have any more plot than 'character thinks'. Considering I'm a Gen writer, my plots suck, and I'm grateful that most readers over look the holes, or that my betas fill them for me as we go along. Mostly, I *am* interested in how the characters interact, and in general, a story will only work for me if I know what it's going to say about the characters. Plot is entirely secondary.

*g* It is hard to say you write Gen when you write Jack. He's pretty much his own fandom and his own genre!