I’d also need to see statistics - without any selection bias introduced by what the researcher finds interesting.
There may be 30 or so “common” patterns that appear globally - that would be very interesting if the total pool of symbols was say 50 but much less so if there are thousands of different symbols.
You don't understand. The other 99,970 symbols are just random doodles. It's the 30 common ones that aren't.
There are instances in South America, North Africa, and Australia, where some prehistoric person took the foot of an animal such as a large bird or lizard, with feet that resemble human hands, and stenciled round it onto a wall. Is the repetition of this trope over wide distances just a freaky coincidence? Yes.
Well, there's probably something mimetic going on, like the idea of stenciling round your hand at all. "Neat! I'm gonna do that too! I'm gonna get my little brother to do it! And my chicken! And this leftover lizard foot!" Memes spread easily. Kilroy was here, nobody writes that one on walls any more, and hands were stenciled over thousands of years, but we have an evolving culture now.
> Kilroy was here, nobody writes that one on walls any more, and hands were stenciled over thousands of years, but we have an evolving culture now.
Not in the relevant sense. Nobody writes Kilroy was here anymore, but we continue to do hand outlines. That's not a practice that has changed over the last 50,000 years.