I think that improvised humor depends on the moment. On a Friday, a week after I emigrated and started a job in the USA, a Company Director (Mr. Hula) and my Manager (Mr. Mulligan) took me (Scot) and an other Brit (Englisher) out to lunch.
The conversation palled as we did not have much in common, but we got onto the subject of humor.
I was explaining my theory that every nationality had another nationality as the butt of their jokes. Brits tell Irish jokes, Irish tell Kerryman jokes, Poles tell Russian jokes and Americans tell Pollack jokes.
I explained that this was an Irish joke I learned in the UK, but as I knew Mr. Mulligan was Irish, I would tell it as a Polish joke.
Mr. Hula announced, "I AM POLISH!"
Too quickly I replied, "Well, I'll tell it really slowly, then."
Mulligan laughed uproariestly. Hula was not amused.
I got fired within the year and was surprised I lasted that long.