Today, plenty of us talk to ourselves, but relatively few of us hear voices. According to one psychologist, as little as 3,000 years ago it was the other way around. Find out about the bicameral mind, and why once upon a time everyone might have been hearing voices.


In 1976, Julian Jaynes came out with an idea that shook the way people understood both themselves and human society — the idea of a bicameral mind. This mind was not the kind of mind that we have today, capable of introspection and musings. It wasn't integrated the way modern brains are; the left half took in information and made command decisions, in language, and the right half obeyed, without real conscious thought. It obeyed even without understanding that it was obeying decisions made by the mind itself. When questioned about why it did something, someone possessing a bicameral mind would say that they obeyed the voice of a spirit, a dead relative, or a god.

Jaynes believed that all ancient people had a bicameral mind, and that this was a common condition of humanity only 3,000 years ago. To provide evidence for the idea, Jaynes pointed to modern day schizophrenics, who sometimes hallucinate voices, as modern-day inheritors of the remnants of bicameralism. Then he turned his eye to history, and pointed out that the earliest religions generally had a variety of spirits, rather than a unifying god. This was evidence of a multitude of gods made up by a multitude of people. Some earlier cultures had a tendency to hear the immediate voices of deceased family members, and even to keep corpses clothed and "fed," because they still heard their family's voices as if they were alive. Jaynes even pointed to bicameralism in the Bible. In the Book of Amos, one of the earliest books, there is no personalization of the narrator, and there is no look at the motives of feelings of anyone mentioned. The book is for the most part a transcript of what God said, what God wanted, and what God would do to anyone who didn't obey. Later books looked much more closely at the psychology of the people involved. Jaynes also pointed to ancient Greek texts. In earlier editions, the gods appeared to the human heroes and either forced them into foolishness or guided them to make the right decisions. These "gods" were the minds of the heroes themselves. Only in later texts, Jaynes claimed, did the style change and the heroes themselves become capable of making their own decisions and harboring their own thoughts.


We have some modern evidence of bicameralism in the behavior of those who have had the communication between the halves of their brain severed. Deliver an image to one half of their brain, and they'll act on it without knowing exactly why. They won't, however, ascribe the command to action as coming from a source outside themselves — which contradicts Jaynes' idea of the bicameral mind hearing voices.

There are other problems with the idea of bicameralism. The disappearance of the bicameral mind, across the world, only a few thousand years ago, would mean that a scattered humanity would have to simultaneously suffer some trauma that would select more integrated minds. And, although monotheistic religions have built up steam lately, there are certainly still polytheistic religions around. There are also still prophets who claim to directly hear the voice of god while still hearing their own thoughts. And so the bicameral mind remains a highly controversial idea - if an intriguing one.

[Via Last Ape Standing and Thomas Forster]