Actually, most modern sociological research that I've read indicates that play, regardless of species, serves two main purposes; introducing the individual to a socialized group by encouraging ad-hoc cooperation and/or coordination (which prepares the young for other activities such as hunting in the case of predators and defense of the group in the case of prey) and also forming a social structure or hierarchy.
As for the rest, humor also has another origin other than aggression, contempt and schadensfreude; defense. Humor can be used to defuse tensions that might arise in a shifting group dynamic by deflecting a situation that has a potential to become more aggressive.
In Response to "Three Unappreciated Demon Slayers" from The Escapist Forum: Thanks for the article. Gamers have no business hating Jack Tramiel -- he may have been at the root of trying to halt the release of the Amiga, but it was under his leadership that the VIC-20 and best selling Commodore 64 were created. Name me any popular game studio or publisher today. Their existence can be mapped somehow right to the C64.
Just one thing: Your account of Jack's departure makes it seem like he ended his rein by ruining the company then high-tailing it out. Jack turned Commodore into a billion dollar company. The price war was not only a personal vendetta against TI, but an attempt to establish the C64 as a de-facto standard. Speculation is a dirty business, but I'll be bold enough to say, had Irving Gould (aka Goa'uld) not forced Jack out, the computer industry would have a different face today.