Paul Ekman, an expert in the field of emotions, has identified four primary emotions that are universally acknowledged: fear, anger, sadness and enjoyment. All of these emotions evoke engagement, but not all of them build a state of being ready to do difficult things, and to think deeply about them, and finally develop new solutions and new knowledge. So, logically, teaching should be nice and pleasant, because enjoyment gives the best results.
But, is it always possible to play during lectures making them funny? Does, in your opinion, enjoyment really have a positive effect on memorizing knowledge, even in case of statistics or econometrics?
Could you suggest some works on this topic?