Here is why crude jokes titillate you

Researchers at the University of Colorado-Boulder found that people tend to laugh at disgusting comedy even including someone’s death or immoral behaviour when they perceive them as unreal and not hurting anyone or anything.

Now the researchers, led by A Peter McGraw, who co-authored the study with Caleb Warren, have come up with three criteria they find could explain why things are funny.
They figured the anecdote or scenario had to be incongruous , benign, and also reconcilable. In other words, there has to be some way to be disgusted by a moral violation and also consider it simultaneously benign.

McGraw thinks the humour rules could explain everything from puns and jokes to slapstick and other forms of comedy.

“We laugh when Moe hits Larry, because we know that Larry’s not really being hurt,” McGraw said, referring to  slapstick. “It’s a violation of social norms. You don’t hit people, especially a friend. But it’s okay because it’s not real.”

The findings could also explain why comedy films tend to have most success in their culture of origin.  “It’s hard to find a comedy that’s funny cross-culturally, because the ways that violations can be benign differ from culture to culture,” McGraw said.