I saw an interview with Jerry Seinfeld recently and he remarked that "crankiness is at the essence of all comedy". Seinfeld stated that all comedy is based in anger - not only that, but anger over things that didn't matter at all and that it was all about trying to express that anger in a way that convinced people. Well, according to a study published in the Christmas issue of the British Medical Journal, Jerry seems to be right on target. What Jerry may not understand is that it is testosterone that fuels the comedic anger.
Professor Sam Shuster recorded the responses of more than 400 people as he rode a unicycle through the streets of Newcastle upon Tyne. He noted that most people responded with a wave or a stare, and about half of them responded verbally. Men were more likely to respond verbally and in a more derisive way. Whereas women expressed admiration of his skill, encouragement or even fears for his safety, only 25% of men responded this way. 75% of men responded with comedic attempts, usually snide or combative. The male response changed with the age of the individual, and the reason Shuster says, is male hormones.
Responses became more verbal during the later teens, turning into disparaging 'jokes' or mocking songs. This then evolved into adult male humour -- characterized by repetitive, humorous verbal put-downs concealing a latent aggression. Young men in cars were particularly aggressive. Professor Shuster notes that this is the age when men are at the peak of their virility. The 'jokes' were lost with age as older men responded more neutrally and amicably with few attempts at a jovial put-down.
I am not convinced that it is true that all humor stems from aggression, for that would not necessarily cover more intellectual humor and it cannot all stem from male agression as one considers the number of female comics that have become part of the culture, but it may be a common human trait that we make fun of things that irk and annoy us. Perhaps comedy is a way to avoid real anger by diverting our anger over seemingly unimportant things into derisiveness which allows us to validate the aggression that something causes us while dismissing it.