Home » Kiosk » Kiosk Article » Julian Jaynes’ Theory of the Evolution of Human Consciousness

Julian Jaynes’ Theory of the Evolution of Human Consciousness

The emergence of consciousness on planet earth is a great mystery and its evolution from animal consciousness to human consciousness has been an enigma. In the last couple of centuries a number of biologists, psychologists, sociologists and scientists have presented a number of theories about human evolution and consciousness. Some of those theories became more popular than others. While Charles Darwin connected human consciousness with biological unconscious, Sigmund Freud with psychological unconscious, and Karl Marx with social unconscious, Julian Jaynes connected evolution of human consciousness with the breakdown of the bicameral mind, the Half God/Half Human mind. Although his theory was a significant contribution, worthy of serious consideration, it did not become as popular as other theories.

Julian Jaynes was one of the original psychologists, philosophers and scholars of the 20th century. Born in Massachusetts in 1920, he studied at Harvard, Yale and McGill, and taught at Princeton University from 1966 to 1990. His book, The Origin of Consciousness in the Breakdown of the Bicameral Mind was nominated for the National Book Award. He died of a fatal stroke in 1997.

Before presenting Jaynes’ theory of the Bicameral Mind, let me set the context by briefly reviewing the theories of Charles Darwin and Alfred Russell Wallace. In his books, The Origin of Species[1] and The Descent of Man[2] Darwin presented a unified theory of evolution and challenged the theory of separate evolutions. Many Christians, Jews and Muslims believed that God created animals on earth while He created Adam and Eve in heaven. After they ate from the tree of knowledge and committed the original sin, they were cursed and sent to earth to reproduce as human beings. Darwin proved that animals and humans had common origins on earth and humans were evolved animals. Darwin highlighted that animals and humans not only had similarities in their bodies but also in their brains and minds. He wrote, “… the difference in mind between man and the higher animals, as great as it is, certainly is one of degree and not of kind.”[2, p.130] He showed that animals exhibited a wide range of intellectual and emotional characteristics similar to humans. Whether it was pain or pleasure, happiness or sadness, jealousy or grief, wonder or curiosity, devotion or love, they were all present in higher animals. He even thought animals could communicate with each other, but that it was nonverbal communication. Humans evolved further than other animals because of their spoken and written language, which enabled them to create art and literature, religion and culture, and become civilized.

Darwin was agnostic about the existence of God and did not believe in divine revelations. He believed in a secular interpretation of life. But Darwin’s secular views were not only challenged by religious clerics, they were also criticized by other biologists, psychologists and scientists. Even his contemporary and great admirer, Alfred Russell Wallace, whose paper on the theory of evolution was presented at the same time as Darwin in 1858, did not agree with Darwin’s secular views. Wallace believed that human consciousness “could not possibly have been developed by means of the same laws which have determined the progressive development of the organic world in general, and also of man’s physical organism.”[3, p. 10] Wallace observed such a miraculous difference in animal and human consciousness that “he felt the evidence showed that some metaphysical force had directed evolution at three different points:
     • the beginning of life,
     • the beginning of consciousness, and,
     • the beginning of civilized culture.”[3, p. 10]

Wallace’s supernatural explanation of evolution was not accepted by all those mainstream biologists, psychologists and scientists who were looking for natural explanations for natural phenomena.

Alongside Wallace’s religious theory of human consciousness and Darwin’s atheistic theory, another theory was offered by Julian Jaynes. In his book, The Origin of Consciousness in the Breakdown of the Bicameral Mind.[3] Jaynes discussed that animal consciousness passed through the stage of the bicameral mind in which humans had Half God/Half Human consciousness, before there was a development of the full human consciousness. During this phase of a few thousand years, human minds routinely heard the voices of gods, angels, spirits and their dead relatives. During that time, the right brain was more active than the left brain. The right brain that heard God’s voice was the executive half, and the left brain, the follower half, received those directions from the right brain and acted on those orders without questioning them. That was the time human minds had not yet developed the capacity to question and challenge. During that phase of evolution, gods were more important than humans. The bicameral mind was not only reflected in the personal lives of people but was also present in their social lives. In bicameral cultures, God was at the centre of people’s lives. In many such cultures God’s house, whether a mosque or a church, a temple or a synagogue, was built in the centre of the town, and people built their houses all around it. Even in people’s homes, humans built a room for God and put different idols there to represent different gods. In bicameral cultures, gods were at the centre and humans were at the periphery.

Jaynes theorizes that hearing the voices of the dead was the beginning of hearing the voices of gods. He writes, “the dead were then called huaca, or godlike, which I take to indicate that they were sources of hallucinated voices … that the dead were the origin of gods is also found in the writings of those bicameral civilizations that became literate.”[3 p. 163]

Jaynes believes that the bicameral mind was only able to cope with small communities and the small problems of small tribes. Each tribe had a God/King who was the chief, and received messages from gods and dead kings to guide his tribe. Jaynes states, “… a new king ruled by obeying the hallucinated voice of a dead king.”[3, p. 176] For bicameral minds, gods were realities and not just fantasies. “The gods were in no sense ‘figments of the imagination’ of anyone. They were man’s volition.”[2, p. 202] But as human beings evolved because of agriculture and developed complex communities, the bicameral mind could not deal with their complex problems and collapsed.

That was the time in history when gods stopped talking to humans. That was the beginning of human consciousness and the development of language, literature and culture. When humans did not hear the voices of gods, they assumed that the gods were angry with them. To please the gods, humans started praying and offering sacrifices. Jaynes is of the opinion that different cults and religions were born after the death of the bicameral mind. When humans heard God’s voice directly, they had a personal authority. After that authority was gone, humans had a need to consult religious leaders and prophets who could still communicate with the gods and receive divine revelations. During that period cult leaders, and prophets had the authority of the gods and scriptures.

As human consciousness evolved and the left brain developed, human beings started relying on their own rational minds and secular conscience, and they began challenging their religious leaders and scriptures. For them their own logic and conscience became their personal authority. Jaynes highlighted that although humans have outgrown the bicameral religious mind and developed a secular consciousness, we can still see the remnants of the bicameral mind all over our communities and cultures. He writes:

We, at the end of the Second Millennium AD are still in a sense deep in this transition to a new mentality. And all around us lie the remnants of our recent bicameral past. We have our houses of gods which record our births, define us, marry us, and bury us, receive our confessions and intercede with the gods to forgive us our trespasses. Our laws are based upon values which without their divine pendency would be empty and unenforceable. Our national mottos and hymns of state are usually divine invocations. Our kings, presidents, judges and officers begin their tenures with oaths to the now silent deities taken upon the writings of those who have last heard them.[3, p. 317]

Although human beings have left the gods behind, yet there are times they feel nostalgic about them and miss them—especially when they are stressed and experience a crisis. That is why it is not uncommon for people to have visions of dead relatives when they are grieving or hear the voices of gods and angels when they are a experiencing a nervous breakdown. Jaynes believed that as human beings evolve and the human mind and personality grow, humans will have less and less need for gods.

Jaynes associated the evolution of human consciousness with the development of language, a sense of “I,” and an ability to reflect and introspect. Such introspection helps develop a sense of self and a unique personality.

Jaynes believed that with the evolution of human consciousness and personality, human beings are able to develop self confidence and trust their own judgment. They would no longer need the authority of prophets and scriptures. The more humans mature, the less they need gods.

If we consider the contemporary world, we can easily see that many communities and cultures are still following a bicameral mind, or need the authority of gods, prophets, scriptures and religious leaders. The changes that individual humans can make in their personal consciousness in a few years can take a few centuries in the collective lives. The evolution of human consciousness has been a slow—a very slow—process.


[1] Darwin, Charles. The Origin of Species. Castle Book: New Jersey, USA, 2004.

[2] Darwin, Charles. The Descent of Man. Prometheus Books: Amherst, New York, USA. 1998.

[3] Jaynes, Julian. The Origin of Consciousness in the Breakdown of the Bicameral Mind. Mariner Book: USA, 2000.