This sounds like a very post hoc, anglo-centric way of interpreting humor in an evolutionary light. I seem to remember that there are many cultures where humor

This sounds like a very post hoc, anglo-centric way of interpreting humor in an evolutionary light. I seem to remember that there are many cultures where humor does not rely as much on an unexpected punchline, but rather on a repeated, expected structure (i.e. catchphrases).