If so, which one are you, and how does this difference make itself felt in your relationship? Is it something that causes friction, or do you feel that you complement each other well?
I ask because I feel like my OH tends to be pretty negative and pessimistic about many things, whereas I take more of a 'glass half full' approach. At times, this makes things quite tense between us, or certainly places us in opposition even on quite small or inconsequential things.