Incongruity Theory Of Humor

The incongruity theory of humor arises from a type of humor or joke that juxtaposes a normal situation or question with an event or answer that is basically a "non sequitur" that isn't anticipated and leads to laughter from the audience.

For instance, there could be a sign in an office stating, "Be Alert!---The world needs more Lerts!" A silly statement, but enough to make a person laugh.