How Do I Know What I Think Until I See What I Say?

This week over at Editorial Ass , Moonrat asked an interesting question about self image of characters in YA stories. Here's the question in her words: Which kind of heroine do you think is better in YA fiction--one with a really positive self-image (to promote self-confidence in teen readers), or one with a flawed self-image (e.g. someone who has always felt like a misfit, who has never been labeled conventionally pretty, etc, to promote reader identification)? The comments are pretty interesting, but I find myself disagreeing with the premise. I don't write, and I don't know many other writers who write to promote an agenda. I'm sure they're out there--the "message" writers--but I don't have any personal experience with them. I, personally, don't write to promote self confidence in readers. That's not to say that I don't care about the effect of characters on readers, because I do. I'm all about characters and their effects o