Maybe. Or maybe they started revering their ancestors because they mistook their memories of them for ghosts that were haunting them. It's hard to imagine the kind of gross errors prehistoric people might have made in their trial and error processes, before the systematic accumulation of knowledge was made possible with writing and literacy.

It's hard to imagine, that is, until we remember how silly we all were as children, and especially how open we were to nonsense. Children are always willing to play and to entertain crazy fantasies as if they were real. Eventually they learn the difference between reality and fantasy, but only because behaviourally modern adults wean them off of the enchanted worldview.