ADVANTAGE:
- convey emotion into thoughts (swaying hips to demonstrate waking, using hand signals to represent other people emotions
- Explain more in detail what you're trying to say. people might get the gist more that way.
DISADVATAGE:
- giving possible worng signals (showing hand signals that might give the wrong imprassion of what was actually taking place)
- Not having an organized language, you'd be hard pressed to find an signal for every type of action. thus there's be actions that would signify two+ body motions.