One thing that bothers me, in RPGs, is that we often act stereotypes. Angry characters shout. Sad characters look sad. We act pastiches of emotion.
The problem is: there's little truth in these stereotypes. Try observing yourself next time you're angry. Chances are you won't shout: you might speak tensely, but you'll try to keep your voice under control. If you're sad, you might try to look happy or become withdrawn, but you probably won't look downcast.
I think that, if we acted better, we'd make our games more interesting and affecting.