It seems to me that humour is everybody's way of keeping sane and standing off from the situations so that they can see it intellectually, as well as emotionally, and I don't know whether you've noticed, but if somebody tells a joke, it's nearly always a mini fantasy.
“The language of the younger generation has the brutality of the city and an assertion of threatening power at hand, not to come. It is military, theatrical, and at its most coherent probably a lasting repudiation of empty courtesy and bureaucratic euphemism.”