Mind scolds:

… imagine an entire city where the majority of people are voice-hearers and there is an elaborate cultural mythology for interpreting the voices as “personal gods”, where hearing divine or special voices talk to you is perfectly normal in every way. Can you imagine it? Jaynes could. But it stretches the imagination. But that’s no reason to think it wasn’t the case. Just because modern people with modern minds not hearing voices find that situation “psychotic” or “crazy” doesn’t mean that bicamerality has always been limited to 1-2% of the population. It was likely spread throughout the population in much greater proportion than it is today. It is in fact part of the human gene pool, which is why schizophrenia today has such a large genetic component. Complicated cognitive mechanisms such as voice hearing don’t just stay in the gene pool for no reason. It suggests that it was adaptive in the not too distant past. And for some people in some cultures, as Luhrmann indicates, it still serves an adaptive function.