The Origin of Consciousness in the Breakdown of the Bicameral Mind is a classic psychology book that poses an interesting, but in my view unlikely, theory that human consciousness is not a product of evolution. Instead, Jaynes believed that it was something developed socially and only recently in brains that had evolved instead for a “bicameral mind.”

The bicameral mind in Jaynes’ theory is a mind that operates much like a modern schizophrenic. The two hemispheres of the brain, right and left, would be disconnected, with each operating essentially separately from each other and with no concept of the “I” or self. The left brain in this theory operates as the closest analogue to our modern self, while the right brain functions as a “god,” issuing dictates to the left brain in the form of hallucinated voices and images.

Jaynes thought that the bicameral mind functioned well only in small societies, where a chief or leader would arise and that individual’s image or voice would impose itself as the hallucinated “god” of the right hemisphere, allowing small societies to form around the “leader,” when in actuality the right hemisphere of the human brain was imagining the commands that the chief would issue were he present.

This bicameral mind, however, could not function in larger societies that began to spring up. Too many competing priests and other lower functionaries arose as intermediaries to the chief, leading to periodic societal collapse as conflicting orders were recieved and larger societies could no longer function. This process was accelerated by the gradual development of writing, which Jaynes thought created an entirely separate mode of thinking. As writing developed, it eroded the auditory hallucinations by weakening the auditory aspects of the mind, shattering the fragile hallucinatory effects somehow by altering which portions of the brain we most frequently use.

Jaynes’ support for his theory is mostly literary and historical. He points to a variety of societies that seem to have suffered from a gradual collapse of the bicameral mind, as evidenced by societal failure and an alteration in their literature to evidence consciousness of the self. The Scythians, for example, suddenly altered their statues and writings to begin to refer to a refusal of the gods to communicate directly with them. The Greeks experienced the Dorian invasions, a series of migrations and attacks that preceded a shift in the Illiad and other oral literature from referring only to actors being driven by the Gods to later literature in which they contemplate their own emotions and basis for acting. The Hebrews went from the God of the Old Testament, who spoke directly to his people, to a God who would no longer appear before them. The Aztecs and Incas periodically collapsed for unknown reasons, abandoning their cities and returning to the surrounding areas.

Ultimately, while it’s a very interesting theory, I see the support as thin. Jaynes supposes that our bicameral ancestors, milling about like cattle, had been thinned from the herd in favor of those who were genetically less inclined to hear voices and better able to function in a modern, post-literate society. This thinning of the ranks left only schizophrenics as the modern remnants of those who used to possess a true bicameral mind. This seems to me to be unlikely given the many isolated tribal peoples who have persisted to this day, often with little contact from the outside world. If the theory of the bicameral mind were correct, we would expect them to behave as Jaynes suggests, given that few have systems of writing. While, as Jaynes points out, there could be some degree of projection at work in the same sense that there is a human tendency to see emotions and motives in animals which are not truly conscious, illiterate tribesman are hardly the passive, hallucinatory creatures suggested by the theory.

A further complication for me is the question of why modern men who are never taught to write do not display these hallucinatory characteristics. The genetic culling of those who hallucinated could only go so far - if the human mind truly did not evolve to display consciousness, and it is a recent consctruction caused by human writing, then an individual who was never taught to write would never be rewired to be conscious.

A related problem is that the rate of literacy has been near universal only recently. At the times suggested by Jaynes for the shift towards the existence of consciousness, only small numbers of people would actually have had any experience with writing - and yet Jaynes points to dramatic shifts that affected entire populations.

My guess is that the alterations in writing to refer to the first person identified by Jaynes were a refinement of language itself, and not the genesis of consciousness. As he points out, language is a recent phenomenon. Complicated emotions and discussion of consciousness cannot become a part of literature until there is a vocabulary with which to describe them - and, as a functional matter, this would be the last aspect of language to develop. Language’s importance is as a conduit for information - Jaynes traces its beginnings to efforts to communicate valuable information such as the presence of threats and how to make tools. Emoting beyond the basics of anger or fear has little survival value, and words for more complicated emotions might have been a long time coming even while the emotions themselves existed. English does not contain a word for shadenfreude, yet we feel it just the same.

Regardless of the merits of the theory, the book is thought provoking and interesting. It’s a great tract on the basics of consciousness and the history of the development of language and the mind.

You can buy the Origin of Consciousness in the Breakdown of the Bicameral Mind online here.

Relate Discussion of the Book’s Theories:

An antecdote about him and a link to a society promoting his work here.

Discussion of the book in relation to a theory that mental processes follow inevitably from physical ones which result in evolution here.

Some discussion of the theory and its application to modern children who hear voices here.

Further attempts to place the beginnings of advanced consciousness here.