I'm unsure what this (Radiant A.I.) comes from, or how it is affected, but I have been playing Skyrim for quite a while, and I've found that its quite perfectly executed. The game folds out different for every player, and it's because there's also a twist of randomness to the game.
I always treat the people in Skyrim as though they are real i.e. I don't steal from them, I don't talk disrespectfully to people, and I don't hurt people who aren't already attacking me. Usually.
This seems to have had a "Karma"-like effect on my character, increasing how well people around me treat me, and even, sometimes, seeming to increase the frequency of good things happening to me in-game.
God Blessed this game, more than you think.