Is there any way of setting your empire's mood toward other empires, so that you can show you are feeling brotherly toward them (or murderous!

)? Does this have any effect on the AI, for instance if an AI empire is annoying you and you start moving your Mood toward them down toward the cooler end of the scale? Or in an MP game, you could use this as a subtle communication of your stance toward other empires?
Also, does it seem odd to anyone else that an AI empire can be feeling murderous toward you, yet maintain your Partnership treaty? Or that they can be feeling brotherly, yet refuse all of your offers to end the current War situation?
SpaceBadger