Bicameralism[Note 1] (the condition of being divided into “two-chambers”) is a hypothesis in psychology that argues that the human mind once operated in a state in which cognitive functions were divided between one part of the brain which appears to be “speaking”, and a second part which listens and obeys—a bicameral mind. The term was coined by Julian Jaynes, who presented the idea in his 1976 book The Origin of Consciousness in the Breakdown of the Bicameral Mind, wherein he made the case that a bicameral mentality was the normal and ubiquitous state of the human mind as recently as 3,000 years ago, near the end of the Mediterranean bronze age.
The Origin of ConsciousnessEdit
Jaynes uses governmental bicameralism as a metaphor to describe a mental state in which the experiences and memories of the right hemisphere of the brain are transmitted to the left hemisphere via auditory hallucinations. The metaphor is based on the idea of lateralization of brain functionalthough each half of a normal human brain is constantly communicating with the other through the corpus callosum. The metaphor is not meant to imply that the two halves of the bicameral brain were “cut off” from each other but that the bicameral mind was experienced as a different, non-conscious mental schema wherein volition in the face of novel stimuli was mediated through a linguistic control mechanism and experienced as auditory verbal hallucination.
Bicameral mentality would be non-conscious in its inability to reason and articulate about mental contents through meta-reflection, reacting without explicitly realizing and without the meta-reflective ability to give an account of why one did so. The bicameral mind would thus lack metaconsciousness, autobiographical memory, and the capacity for executive “ego functions” such as deliberate mind-wandering and conscious introspection of mental content. When bicamerality as a method of social control was no longer adaptive in complex civilizations, this mental model was replaced by the conscious mode of thought which, Jaynes argued, is grounded in the acquisition of metaphorical language learned by exposure to narrative practice.
According to Jaynes, ancient people in the bicameral state of mind would have experienced the world in a manner that has some similarities to that of a person with schizophrenia. Rather than making conscious evaluations in novel or unexpected situations, the person would hallucinate a voice or “god” giving admonitory advice or commands and obey without question: One would not be at all conscious of one’s own thought processes per se. Jaynes’s hypothesis is offered as a possible explanation of “command hallucinations” that often direct the behavior of those afflicted by first rank symptoms of schizophrenia, as well as other voice hearers.
Jaynes built a case for this hypothesis that human brains existed in a bicameral state until as recently as 3,000 years ago by citing evidence from many diverse sources including historical literature. He took an interdisciplinary approach, drawing data from many different fields. Jaynes asserted that, until roughly the times written about in Homer‘s Iliad, humans did not generally have the self-awareness characteristic of consciousnessas most people experience it today. Rather, the bicameral individual was guided by mental commands believed to be issued by external “gods“—commands which were recorded in ancient myths, legends and historical accounts. This is exemplified not only in the commands given to characters in ancient epics but also the very muses of Greek mythologywhich “sang” the poems. According to Jaynes, the ancients literally heard muses as the direct source of their musicand poetry.
Jaynes asserts that in the Iliadand sections of the Old Testament no mention is made of any kind of cognitiveprocesses such as introspection, and there is no apparent indication that the writers were self-aware. Jaynes suggests, the older portions of the Old Testament (such as the Book of Amos) have few or none of the features of some later books of the Old Testament (such as Ecclesiastes) as well as later works such as Homer’s Odyssey, which show indications of a profoundly different kind of mentality—an early form of consciousness.
In ancient times, Jaynes noted, gods were generally much more numerous and much more anthropomorphic than in modern times, and speculates that this was because each bicameral person had their own “god” who reflected their own desires and experiences.
He also noted that in ancient societies the corpses of the dead were often treated as though still alive (being seated, dressed, and even fed) as a form of ancestor worship, and Jaynes argued that the dead bodies were presumed to be still living and the source of auditory hallucinations. This adaptation to the village communities of 100 individuals or more formed the core of religion. Unlike today’s hallucinations, the voices of ancient times were structured by cultural norms to produce a seamlessly functioning society.
Jaynes inferred that these “voices” came from the right brain counterparts of the left brain language centres; specifically, the counterparts to Wernicke’s area and Broca’s area. These regions are somewhat dormant in the right brains of most modern humans, but Jaynes noted that some studies show that auditory hallucinations correspond to increased activity in these areas of the brain.
Jaynes notes that even at the time of publication there is no consensus as to the cause or origins of schizophrenia. Jaynes argues that schizophrenia is a vestige of humanity’s earlier bicameral state. Recent evidence shows that many schizophrenics do not just hear random voices but experience “command hallucinations” instructing their behavior or urging them to commit certain acts.[full citation needed]
As support for Jaynes’s argument, these command hallucinations are little different from the commands from gods which feature prominently in ancient stories. Indirect evidence supporting Jaynes’s theory that hallucinations once played an important role in human mentality can be found in the recent book Muses, Madmen, and Prophets: Rethinking the History, Science, and Meaning of Auditory Hallucination by Daniel Smith.
Breakdown of bicameralismEdit
Jaynes theorized that a shift from bicameralism marked the beginning of introspection and consciousness as we know it today. According to Jaynes, this bicameral mentality began malfunctioning or “breaking down” during the 2nd millennium BCE. He speculates that primitive ancient societies tended to collapse periodically: for example, Egypt’s Intermediate Periods, as well as the periodically vanishing cities of the Mayas, as changes in the environment strained the socio-cultural equilibria sustained by this bicameral mindset.
The Bronze age collapse of the 2nd millennium BCE led to mass migrations and created a rash of unexpected situations and stresses which required ancient minds to become more flexible and creative. Self-awareness, or consciousness, was the culturally evolved solution to this problem. This necessity of communicating commonly observed phenomena among individuals who shared no common language or cultural upbringing encouraged those communities to become self-aware to survive in a new environment. Thus consciousness, like bicamerality, emerged as a neurological adaptation to social complexity in a changing world.
Jaynes further argues that divination, prayer, and oraclesarose during this breakdown period, in an attempt to summon instructions from the “gods” whose voices could no longer be heard. The consultation of special bicamerally operative individuals, or of divination by casting lots and so forth, was a response to this loss, a transitional era depicted, for example, in the book of 1 Samuel. It was also evidenced in children who could communicate with the gods, but as their neurology was set by language and society they gradually lost that ability. Those who continued prophesying, being bicameral according to Jaynes, could be killed.Leftovers of the bicameral mind today, according to Jaynes, include mental illnesses such as schizophrenia and the hallucinations present in patients with split brain syndrome.