Has Human Mentality Changed? Part 1 of 2: Neuroplasticity and Jaynesian Psychology


The media and scientific journals give much attention to “neuroplasticity” (the brain’s innate ability to form and reorganize synaptic connections in response to learning or injury), “neurodiversity” (variations in the brain regarding sociability, learning, attention, mood, and other various mental functions), “neurotypical,” and “neuroatypical.” From an intellectual historical perspective these terms elicit interest because they call into question, at least in a very general sense, what has been a foundational concept of the social sciences: Psychic unity. Introduced by the anthropologist Adolf Bastian (1826‒1905), psychic unity was further conceptualized early in the twentieth century as an intellectual assault on racism by enlightened, well-meaning, anthropologists. Psychic unity is a universalist idea postulating that that human mentality is more or less the same everywhere; it challenged the previously dominant view of social Darwinism that viewed societies climbing a ladder of civilizational progress. At the top were late-nineteenth century industrially-advanced societies whose technological prowess was assumed to grant them superiority. In the case of northern European and American powers, it was assumed that their “white,” Christian identity explained their success (though Japan, which was not far behind the Euro-American sphere in terms of “progress,” obviously did not rely on white racialism and Christianity to account for its achievements). Less successful societies had not acquired the cognitive capabilities to compete with those higher up the ladder of civilization. The premises of psychic unity are still prevalent among not a few psychologists and configures assumptions that restrict research, despite recent interest in neuroplasticity and neurodiversity.

Neuroplasticity, neurodiversity, etc. seem to take the individual as the basic unit of analysis. But what if we expanded the discussion to the societal level and, additionally, give culture, socializing experiences, and historical changes more prominence to add nuance to the theorizing, i.e., rather than neuroplasticity, we could speak of neurocultural plasticity. If there has been one researcher who arguably has done just that, it is the late Julian Jaynes.

Relying on a multidisciplinary approach that resulted in an ambitious archaeopsychological project (The Origin of Consciousness in the Breakdown of the Bicameral Mind, 1976), Jaynes argued that until about three millennia ago people were preconscious, lacking subjective introspectable self-awareness. Decisions were made, behavior governed, and society managed by what today we call audiovisual hallucinations generated by the right hemisphere and communicated to the left hemisphere (hence “bicameral”).

In the past these experiences were interpreted as supernatural visitations. Jaynes theorized that changes in hemispheric intercommunication and language regions explained differences in mentality. But what is significant in his arguments—and often overlooked or simply misunderstood—is that interhemispheric communications were shaped by cultural and historical forces, not biological evolution. In any case, Jaynesian psychology, and other unconventional, peripheralized perspectives (e.g., the “primitive mind” of Lucien LévyBruhl, 1857–1939), boldly put on the table of inquiry psychic plasticity and diversity rather than psychic uniformity and unity.

What Does Psychic Diversity Mean?

Two caveats. First, psychic diversity, like all ideas, cannot be taken to extremes. Arguably it has animated misguided utopian dreams of political reformers, intoxicated by human perfectibility. Overly-ambitious plans for social re-engineering have turned into the nightmares of socialist and communist systems, still seen in incorrigible holdouts like North Korea. Second, the differences in mentalities throughout history and across cultures are one of degree.

In concrete terms, psychic plasticity means several things. Let’s start with an uncontroversial observation on which we all would agree. People do not all share the same assumptions, opinions, views, beliefs, and sentiments. No two individuals, even if they speak the same language, have been socialized within the same culture, and have had the same experiences, agree on everything. For example, individuals within the same family may have different views and ways of thinking about any number of topics. A daughter and her parents may have widely different opinions about who will make a good son-in-law. As any parent knows, different generational perspectives reveal different minds. This difference in minds become greater between individuals from different socioeconomic classes within the same society. Cross-culturally, these differences grow even greater. Not unexpectedly, moving backward in time increases psychological variation, and greater historical leaps reveal remarkable diversity. Such variability is more fundamental and consequential to an appreciation of homo sapiens than common understandings and the ability to empathize with our predecessors may seem to indicate.

Consider the reactions one would probably solicit from another person who is being instructed on how to use a computer. Teaching someone who grew up in the same culture and within roughly the same generation as oneself would probably acquire the skills relatively quickly (literacy and its concomitant abilities, manual dexterity and typing skill, basic understanding of office equipment such as electrical sockets, buttons, etc.). This is because there are many understandings—structured by the same cultural, political, economic, and technological forces—that are shared between the teacher and student. Now consider teaching someone from the late Victorian period. This student would undoubtedly be amazed by the computer and its applications. But what if it were possible to go back in time further, say 3,000 years ago, and meet a non-elite, uneducated commoner in Mesopotamia. Though it certainly might be possible to successfully teach this person, it would be far from easy, requiring a very long training period. Consider all the disadvantages the student would face: Illiterate (and thus lacking literacy’s highly-powered concomitant abilities, e.g., alphabetical sorting and ordering, rationalized classificatory schemes, access to vast quantities of data, highly abstract generalizing and manipulation of information, etc.); lack of fine finger coordination; an ignorance of how to utilize office equipment. The instructor—at least in my opinion—would probably conclude that this student was just not difficult to teach, but possessed of an entirely different mentality. Student and teacher would certainly be able to discuss a large range of mundane—and perhaps even not so mundane—subjects. However, because of the historical and cultural gap, they would nevertheless be separated by an unfamiliar sea of knowledge and a profound divergence in cognitive style would exist between them. The ability to communicate does not necessarily equal similar thinking.

In Part 2 of “Has Human Mentality Changed?” I look at some of the implications of psychic diversity.

Learn more about Julian Jaynes’s theory by joining the Julian Jaynes Society and reading our publications.

Brian McVeigh

Brian J. McVeigh

Brian J. McVeigh has a MS in counseling and a PhD in Anthropology, Princeton University. He researches how humans adapt, both through history and therapeutically. The author of 17 books, his latest publication, "The Self-healing Mind: Harnessing the Active Ingredients of Psychotherapy" (2022), adopts a Jaynesian framework to explain how therapy works. He works as a licensed mental health counselor.

2 thoughts on “Has Human Mentality Changed? Part 1 of 2: Neuroplasticity and Jaynesian Psychology

  • July 15, 2021 at 7:15 pm

    Thank you Dr McVeigh for taking on this topic of neurodiversity and the assumption of psychic unity that seems to be an unexamined premise in so many different corners of our world today. I am writing though, because your example of trying to teach a Mesopotamian person from 3000 years ago how to use a computer does not seem to me to demonstrate anything truly “neurodiverse” about this person compared to the teacher. It seems that the problem would simply be a large amount of ignorance of modern technology. I don’t understand how the example you gave would show anything truly different about the teacher and the students mentality. To put it a bit differently, even the though there is a huge difference between the two in technical knowledge, I don’t see any reason based on what you are saying that the student and teacher could not still have a very similar mind in which they both possess “subjective introspectable self-awareness.” What am I missing?

  • July 18, 2021 at 2:41 pm

    Thank you for that comment. The neurodiversity arises because of the huge “cultural” gap between the conscious teacher (from our modern times) and the Mesopotamian peasant. However, the “cultural” difference between these two individuals is of a magnitude that points to a radical difference in psychological processing. The mind is not just neurological. “Mentality” is configured not just by neurology but by culture (what is learned). This was the key point of Jaynes. It’s not just a matter of “technical knowledge” or degree of knowledge. It’s a matter of how even basic numeracy, literacy, and scientific knowledge radically enhance hypotheticality and, for example, the ability to evoke virtual places such as mind-space (a place where simulated entities dwell). Even in relatively modern times differences between nonliterate peasants and urbanized, semi-educated workers could be salient. In any case, per the historical record, there’s very little evidence that before the first millennium BCE Mesopotamians possessed subjective introspectable self-awareness. This illustrates a certain neurodiversity. This is reflected in the remarkable absence of the exploration of philosophical themes, unquestioning acceptance of gods, lack of skepticism, and underdeveloped psychological terminology (mind-words).

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