Laughter is a connection between all humans. We all laugh. And it appears that we have been laughing at the same types of things for years and years.. I found this list of the ten oldest jokes. Some were funny, some not so funny. I haven’t toured the whole site so I don’t know how kid friendly it is, but that page was OK.
It does remind me of a story I read years ago. A scientist was studying humor and came to the conclusion that it was part of an extra-terrestrial project. I just can’t remember who wrote the story or where/when I found it. The conclusions in that story were a bit different than the oldest jokes though… I’ll have to find it know and share the author/story title.