Here's what we do know: 1) It's a fact that pre-modern humans didn't just believe in deities but interpreted their world through them. If you were Ancient Greek and feeling love it was because Eros or Aphrodite was causing it. This is true across cultures. Judaism has a saying about how there is an "Angel" behind every blade of grass. The saying is implying that there is an anthropomorphic entity behind every object and action in the world.
2) You see this anthropomorphic interpretation of the world at the pre-operational stage of child development. Toddlers anthropomorphize the world in a similar way which suggests that this way of seeing the world is not socialized but a biological stage most of us go through.
With that said I don't know what a "Bicameral" mind is. People will have different ways to interpret these data points.