Hello !
Humor is a new way to make the students energetic, creative and positive. It's a healthy method, profitable and sometimes a necessary. It gives great feelings and many benefits as it facilitates the exchanges, improves communication and releives boredom.
On the other hand, it can become an opportunity for some bad students to exagerate on laughing, then the session might be a waste of time.
All in all humor has negative and positive results on studying, it only depends on how the people using it are. And being over-serious isn't a good idea.
As far as I am concerned, if it's used appropriately, humor can be an excellent teaching tool.
:)
