On the Bioware forums, somebody told me that morale is affected by many environmental factors such as the presence of strong or weak enemies, and also by the individual characters' preference for the kind of environment they're in -- dungeon, forest, city, and so on.
None of this is explicitly part of the game rules, but since a lot of you guys have done work in the mechanics of the game, I'm wondering if there's a list floating around of the individual "morale profile" of the NPCs. Exactly how much lower than everyone else's is Khalid's base morale? Is he especially likely to suffer morale failures in dungeons? And so on.