Hooligan House just uploaded a video to You Tube that we think you will find interesting. In it, Duke uses “neutral” body language signals to let Maggie know he doesn't want to play. She’s very persistent and doesn’t give up right away. First, Duke yawns, then he turns his body away from her, then he "freezes", and at last he yawns again. Through it all, his tail is wagging to let her know it isn't that he doesn't like her, he just doesn't feel like playing right now. When she finally gets the message, Maggie lies down and yawns too. “Okay, be boring then!”
This is classic silent dog communication and it’s the kind of thing I look for when I am doing canine temperament evaluations.
Watch the video here: http://youtu.be/Q9X6vseSrpE