If There Is No Non-Verbal Communication

When I read about non-verbal communication in Academic Encounters, which is used in EAP 1 core class, there are many ways of non-verbal communication. I imagined that if people do not use non-verbal communication in conversation, what will happen to them? It will be hard to express their emotion and will be very awkward. Here are interesting instances. If I am just standing or sitting like a robot or a skeleton in a science lab during conversation, how does my friend feel? It looks like a "conversation machine." Or if someone tries to propose to his or her partner without non-verbal communication, how does the partner show reflex? Does it work well? I do not think so. I think that non-verbal communication is an important part in conversation like an ingredient in a meal. Delicious food needs a good source, and awful food has a bad source. I want to ask to my classmates, "was it an interesting subect in core class?" In addition, not very important, we can make a game that only uses a non-verbal communication with time limitation. The person who is smiling or laughing first is the loser. It will be very fun.
Sungu Kim