I'm always amazed that juries ever come to an agreement at all, given all those different kinds of personalities and temperaments thrown into one room.
I think a lot of how juries work depends on the diplomacy of the foreman or forewoman. I know there were a couple of people I just couldn't deal with, a couple of "I got nothing else to do so I'm stonewalling types, so I asked one of the guys to help me out.