I don't know about that, I think cave painting was highly meme driven.

Chauvet Cave and Lascaux are similar (lots of overlapping paintings of large animals), but some 16,000 years separate them. Is that individual self-expression? It looks to me like entrenched tradition.

Stencil paintings of hands are a common theme, but bizarrely are found all over the world: Argentina, France, North Africa, Australia. This too can only be a meme, I think. Possibly the method, spitting out paint, was the meme, and the idea of making stencils of hands arose naturally by accident in all these places, but even then there is no sign of real individual self-expression going on. It's also intriguing to me that three of the places I mentioned (on three different continents!) include stencils of animal hands (large birds or lizards).

Maybe. But I feel that the stuff our ancient ancestors did on walls is a different class of activity to that which we now call art. I suspect that their paintings were done as a votive: maybe as part of a prayer or a ceremony.

There are too many things that are grouped under the same word: 'art'. Objects which serve different functions should not share the same name.