So, that makes it more remarkable that what you almost never ever find in this kind of painting are human faces. Possibly there will be human forms... humans hunting and running and swimming, having sex and giving birth... but the humans are like abstracted shadows. Sometimes with pinheads, hardly ever with eyes. And practically NEVER a face.
It's very tempting to make up a taboo about drawing faces. A cultural rule, but I think it has to go deeper than that.
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