Wonderful, insightful write up on a fascinating topic.

It's seems to be conventional wisdom today to dismiss Jaynes' analysis based on his embellishment of a significance of the neurological morphology of the corpus colossum. But how well does his analysis hold up when morphology is simply sidelined into the idea a neurological module of unknown nature and examined linguistically?

For example, it seems we have language today for aspects of self that were in ancient times regarded as other.

There's some studies into the linguistics of color sensation which seem analogous to the linguistics of the self which you term the theory of mind.

In Lacanian psychoanalysis, there's an idea of a "mirror state" of development of the self where infant consciousness develops awareness of a distinction between self and other when the father figure begins to appear as an interloper on the self's attention for the portion of the infant's sensation that was at birth bonded to the mother. IOW the infant mind must discover that mother is not him due to external influences which compete for her attention.

Such effects occur in a number of domains of psychology and perception.

There's a relatively well-known book about such identity confusions in a clinical setting titled the Man Who Mustook His Wife For a Hat.

There's the Carousel Precognition.

There's phantom limb, effects of lobotomy, etc.

What's interesting to me is that since ancient times, we collectively have moved the "other" of mind out into media devices. These devices talk to us in the mental likeness of others, but which do not exist as such in even the slightest resemblance to a person: the structure of a television couldn't be further from a person, but you never find anyone in ordinary surroundings who A) exhibits slightest confusion that there is no person in the device-- where the device itself is but the barest topography of interpersonal reality-- and B) who questions for even moment the believability of the interpersonal as presented by the device. The voice of the device-other is perfectly assimilated by the viewer.

I suggest that our adaptation to TV (facsimiles of all kinds) is quite weird and unexpected if you think about what's going on between the person and the device, but try having a dialog about this with anyone who hasn't heard of Marshall Mcluhan! Moreover AI chat is far weirder, even if you have heard of McLuhan!

Thanks for the fascinating book report.

P.S. The conceit of "the book Jaynes should have written" is a risky gimmick for your report that I expected to fail, but you pulled it off.