When I was about eight years old and suffering from a particularly nasty case of mononucleosis, I spent a great deal of time at home. My Doctor prohibited me from school on the grounds that I would die due to my hyperactive behavior.
I felt too miserable to go to school anyway - even sitting up caused pain in the back and guts, so I'd usually lay propped up against something and watch TV, play some Atari or Nintendo games when I had the strength to do so, or, periodically, lay propped up under my computer desk and use the shelf below the desk as an impromptu desk. While down there, I would write in little spiral notebooks whatever things seemed important to an inquisitive 8-year-old mind.
One week in particular, watching an A&E's "Evening at The Improv" marathon, I found myself noticing connections between what were good comedians and which were bad - the ones that got a good audience reaction and still amused me (after 6 hours of standup) were considered "good" for the purposes of these observations.
I began to write down (admittedly childish) scholarly observations about things like the "rule of three" and what I called a "serial list joke" (three guys walk into a bar, people serializing related things then breaking the pattern with either the third or fifth element outrageously incongruous. I wrote about surprise, self-referential comedy, prop comedy (and the violation of expectation associated with it) and pretty much what anybody who has any intention of going into standup observes on their own. I used these principles later to great effect to amuse friends and family (when applied judiciously and not heavy-handedly - this was another of my notes.)
From time to time, I'll be watching standup and catch one of these classical archetypes I noted in my childhood. A side-effect of all this observation one particularly ill week of childhood is that I now have an interest in the mechanics of comedy - when I particularly like a comedian who doesn't use these standard mechanisms for humor, I try to figure out why.
It turns out I'm not the only one at all. The mechanics of humor have been analyzed over twenty-five hundred years of western (and near eastern) writing alone - not only what we laugh at, but why we laugh at all. Reputedly (I cannot find a single citation) Aristotle said that "only the human animal laughs." This is a stock traditional introduction to mentioning that rats, dogs, chimps, bonobos, gorillas and orangutans all laugh as well. I'm further convinced that other animals have a sense of humor, including all higher predators (especially cats.) Squirrels and cats both have in common a sense of humor, mischievous pranking and shame. (This is strictly anecdotal observation, but when a squirrel acts enraged because it noticed you saw it fall off a branch and land on its face, what else do you call it?)
Laughter is called the best medicine, and I'd have to say that's only true if you don't have whooping cough or a body cavity injury. At any rate, it makes a good antidepressant in dogs. Laughing will improve a human's mood if sitcom laugh tracks are any indication - the show seems funnier, even if it's less humorous than a similar show without a laugh track. Laughter is relaxing and healthy therefore, just so long as it doesn't kill you.
Er, that's all I've got. No conclusions.