Dennett was also influenced by the (controversial) theory from Julian Jaynes that consciousness is possibly something that emerged in humans much more recently in human history. I’ve had a copy of the book on my shelf unread for a couple of years so I probably won’t speak to it accurately, but I find it a fascinating idea.

Main idea is that human brain has two halves, abs consciousness arrived from auditory hallucinations formed in one half of the brain, and acted on by the other half.

I think one of the arguments here is how humans centuries ago heard voices of gods/angels etc. He argues that this was the bicameral mind in action. I think he has another linguistic analysis that argues that human consciousness emerged around the time the Iliad was composed.

If anyone is interested, this afterword where he covers some criticisms of his ideas is a good entry point: https://web.ics.purdue.edu/~drkelly/JaynesOriginsConsciousne...