I think it’s important to point out that the bicameral mind is one theory, but that doesn’t necessarily mean it’s true. One of its major criticisms is that it suggests consciousness only arose in humans around the time we started writing about it, and that it didn’t exist in humans before then. It’s also entirely possible that humans were conscious way before that, but when we started writing about it was just when we developed the cultural concept of what consciousness is.

The theory also seems to imply there is something special about human metacognitive processes compared to other animals, which would therefore imply that animals are not conscious. That seems weirdly reductive when various non-human animals show some evidence of self-awareness (mirror spot test, Alex the grey parrot).

It’s a nice theory which ties lots of things together, but it’s no more true than any other theory of consciousness at the moment.