Off-color humor is certainly not new: some of the earliest recorded jokes, told thousands of years ago, deal with things that people do in the bathroom or the bedroom. What makes these jokes funny?
What makes any joke funny? Experts say that humor is based on incongruity. That is, jokes are based on surprise, on elements that don’t go together. For example, a small child who talks like an educated adult, or a respected adult who acts like a child.
Yet the elements must still have a connection with real life. When he was a little boy, my brother used to tell a joke with the punchline, “Pass… the… soap… No soap! Ray… dee… oh!” That was not humor, it was nonsense. The joke was on anyone who tried to figure out the joke. We think the precocious child is funny because we’ve heard educated adults say the same things. We think the respected adult is funny when he sticks his tongue out or cleans her nose because we know children who act like him or her.
So why are dirty jokes funny? Because they have built-in incongruity. Every one of them talks about things that people don’t talk about in polite company. We automatically think, “I can’t believe we’re talking about this!” They don’t fit in with our normal conversations. Just hearing them is incongruous.
I’ve only looked at one issue of the soft-porn men’smagazine Playboy, just to say I had done it. Men protest to their suspicious wives that they only read it for the articles. Judging from the issue I saw, they certainly don’t read it for the cartoons. I remember several of them, only because I read them over and over, trying to figure out why they were supposed to be funny. But they were dirty and incongruous. Dr. Judith Reisman and her researchers studied decades of such magazines, every issue, and I can only recall one joke they cited that I found remotely humorous.
Once I understood the nature of humor, I realized that dirty jokes are cheap humor. Not merely low-class or coarse, but cheap in the sense that they don’t cost much. Because every dirty joke is incongruous, dirty jokes get a laugh even if they’re poorly told, even if they wouldn’t be funny if the subject matter were different. That makes indelicate humor a delicate area for writers who want to write well. Using it can make you appear funnier than you are. Better: learn how to be truly funny, without having to depend on easy subject matter.