I guess the latter. I didn't consciously force myself to go out specifically to lessen my stuttering, I just wanted to be less like a lone wolf. I always hated it though that when I had a bad stutter, it suddenly made me the centre of attention. The self-confidence and better mood I got from my presence being appreciated around other people helped a lot. I still stutter noticeably in most social situations, but noticed most people don't mind.