One thing that I didn't see when reading the posts to this discussion is that when a person hikes solo, I think that they tend to prepare more and probably approach things on the trail a little more cautiously, because they are alone. Not necessarily with trepedation, but maybe paying more attention to the little voice in their head, telling them whether or not the situation is safe. Maybe I'm wrong, but when I go solo, I tend to approach things with a lot more thought, from preparation to execution.
Oz