The main evolutionary significance of humor is that it gets us from the closed mode to the open mode quicker than anything else.
John CleeseAll right, but apart from the sanitation, medicine, education, wine, public order, irrigation, roads, the fresh water system and public health, what have the Romans ever done for us?
John CleeseA lot of humour is about just enjoying life and spontaneity and because you make a joke that puts somebody down - we're always teasing each other. It's with affection. It's nasty teasing that we - not all teasing; nasty teasing you cut out.
John CleeseWe all operate in two contrasting modes, which might be called open and closed. The open mode is more relaxed, more receptive, more exploratory, more democratic, more playful and more humorous. The closed mode is the tighter, more rigid, more hierarchical, more tunnel-visioned. Most people, unfortunately spend most of their time in the closed mode.
John Cleese