I also think there is a gradual spectrum of people from dominant to submissive. Personally I want to be dominant towards men I find less masculine than me and submissive towards those I find more masculine. I think I am slightly more submissive, but I do not have enough experience to be sure.
I think most men look dominant, but that could be because the sex stereotypes forces men to hide their submissive side. If most people are inclined to be submissive that is good, in my opinion have to share the master with other slaves makes the slave experience stronger.
RE: What Causes Dom/Sub Sex Fantasies?