The Astonishing Prefrontal Cortex: Part Two – Geniuses Point the Way
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| By ChatGPT. |
The evolution of human cognitive architecture represents one of the most remarkable developments in natural history. Following the model expressed by British archaeologist Steven Mithen in his fabulous work The Prehistory of the Mind (1996), we can trace how early human cognition evolved from separate domains into an integrated system. However, this development gains new significance when viewed alongside the pre-adaptive evolution of the PFC and the language centers. Mithen's model has its critics and is controversial but it is in the neighborhood of what I suspect is accurate. It is the right way to think about the issue even if some of the specifics are wrong. It is a complete, sophisticated system of scientific hypothesis, and enjoys the strengths (and weaknesses) that comes with that approach.
By 1.9 million years ago, early humans had developed a cognitive foundation built on general intelligence combined with specialized capacities. This early architecture featured distinct cognitive domains operating independently - like separate computers that couldn't yet share data. The foundation included “general” intelligence for basic problem-solving and “social” intelligence for group dynamics. These were augmented to some degree by a basic understanding of natural history (these berries make you sick) as well as rudimentary technical capabilities (you can make a sharp stone like this), though most persons did not know much of anything at this point in time beyond how to increase their chances of surviving in an extremely dangerous world.
Social intelligence emerged as a primary driver of early human development. As Mithen notes, social language developed millions of years ago but remained confined to social interactions, mostly by observation and imitation, our language was limited as were our thoughts. This aligns with my belief that Broca's and Wernicke's areas initially evolved for social communication rather than abstract thought, though they enabled the rise of complex language and abstract thinking gradually over thousands of generations.
As I previously indicated in my first astonishment, the PFC's development was likely driven not by cognitive demands but by anatomical changes which in no way intended brain change to be their result (!), possibly bipedalism and forward-facing stereopsis or binocular vision (or something of that nature).
Suddenly, we saw ourselves oriented in space completely differently our ancestors. This created what I've termed "unused neural real estate" - sophisticated brain structures that existed before their ultimate need or use emerged.
The second astonishment occurred when the PFC reached its present anatomical form just as Broca's and Wernicke's areas more or less simultaneously matured. This alignment was also unintended but was, nevertheless, a magnificent trivergence of advanced brain regions interacting to propel language and abstract thought. This enabled new types of intelligence as well as an unprecedented level of integration between intelligences within the vast and unpopulated PFC, expanding human imagination, introspection and informative story-telling skills.
As Mithen explains: "Those individuals who could exploit these invasions to increase their own knowledge about the non-social world would have been at a selective advantage....These talkative individuals were gaining their selective advantage by exploiting the non-social knowledge of other individuals by using language, as opposed to relying on behavioral observations alone. As a consequence, social language would very likely (in evolutionary time) have moved to a general-purpose language; my guess would be in the time period between 150,000 and 50,000 years ago." (page 187)
The “talkative individuals” Mithen mentions were mostly what we would call geniuses today. Other geniuses existed from time to time, of course, exceptional in making tools or constructing shelter or healing illness but, generally speaking, these geniuses hardly ever met one another and discovered things in isolation. Over time, however, more people acquired language and the resulting explosion of abstract thought inside their PFC. Mithen believes non-social intelligence “invaded” social intelligent by “snippets” at first. But, since nothing was happening very quickly, geniuses rarely knew one another the way they easily can today. It took millions of years for communication to grow more complex and, more recently, to colonize unused PFC territory.
According to Mithen, separate social intelligence and natural history intelligence became fully evolved about 100,000 years ago, with technical intelligence integrated fairly soon (in evolutionary terms) after that, some 60,000-30,000 years ago depending upon the culture's locations and available resources, says Mithen. This set up presents the circumstances for the third astonishment, a cultural explosion within the past 10,000 years unlike anything before in human evolutionary history – the emergence of the contemporary mind through history. From mass farming of selected crops to mass use of tiny silicon chips.
The universality of this cognitive development is evidenced by its independent emergence across human populations. The Neolithic period, for example, provides particularly compelling evidence through burial practices found in numerous locations that would likely have had no knowledge of or interaction with one another. As cited in Inside the Neolithic Mind (2005) there existed: "certain powerful people, those believed to have insight in spiritual matters, who kept the customs alive, explained them and decided on whom extra ritual was to be lavished." (page 79) This was roughly 8,000 years ago, though time periods varied across our wide geography.
These "powerful people" represent early geniuses (or at least charismatics) who were pioneering new ways of using their PFC, creating frameworks for abstract thought that others could, glacially but eventually, follow. It was slow because abstract thought cannot be clearly learned by observation and imitation, the way most people learned most things (and all children do still today). That they were viewed by others as “powerful” is a perfect description of how the rest of the somewhat bewildered tribe viewed/respected them for their strange abilities. All over the world, powerful people and charismatics were effectively building bridges between social intelligence and abstract reasoning, using social frameworks to understand non-social realities per Mithen.
This perspective challenges traditional models of evolution by suggesting that our most sophisticated mental capabilities were not a matter of natural selection. Rather, they emerged as we discovered how to use pre-existing neural structures. The implications are profound: if it took over 100,000 years to begin utilizing abstract thought and complex language, how much latent capability have we yet to discover?
The historical record clearly indicates that brain development and our understanding of it leads to emergent (neurodivergent) astonishments. Our brains have been waiting for us for countless ages, there is no reason to believe the PFC is maxed out. Though it is surely being tested today like never before, we only started figuring it out about 10,000 years ago. That is no time at all in terms of our overall evolution! It is a matter of perspective. The way we use of brains is not very old, it is something very new.
The fact that these developments occurred independently across cultures (like the development of diverse languages, beliefs, stories, alcohol, medicine, tools, following similar patterns but expressing themselves in culturally specific ways) suggests they represent fundamental aspects of human cognitive potential rather than merely cultural innovations. Mithen argues for a 65 million year perspective on our contemporary mind. From such a position it is easy to postulate that we are still growing into the comparatively recent PFC, the brain is evolving more rapidly thanks to spoken and written language.
Archaeological evidence reveals that exceptional individuals were pushing the boundaries of human cognition long before written history. These early geniuses weren't simply clever users of existing knowledge - they were cognitive pioneers, venturing into new territories of abstract thought. The domestication of plants and animals provides compelling evidence of this pioneering intelligence. As noted earlier, the person or people who first began this process had to envision how a barely edible grass could become a nutritious food staple through selective breeding. This required not just intelligence, but remarkable abstract thinking and long-term planning abilities.
These early agricultural geniuses were essentially prehistoric geneticists, selectively breeding and cross-pollinating without any formal understanding of the process. They had to recognize patterns over multiple growing seasons, understand the relationship between seeds and mature plants, and develop systematic approaches to cultivation - all achievements that required sophisticated language skills and abstract thinking.
As Mithen explains: "But as soon as language started acting as the vehicle for delivering non-social information and ideas into the domain of social intelligence, reflexive consciousness could also get to grips with the non-social world. Individuals could now become introspective about their non-social thought processes and knowledge...The first step towards cognitive fluidity appears to have been an integration between social and natural history intelligence..." (pp. 191-194)
Basically, for Mithen “cognitive fluidity” designates the human ability to use multiple intelligences simultaneously to create complex thoughts and emotions. It is a kind of cognitive “juggling” that none of our ancestors could experience. Except for rare genetic mutations and the infrequent birth of geniuses, we had no fluidity at all. We could probably still get “lost in our thoughts” but each of us possessed far fewer “thoughts” and for longest time we would think about nothing at all but for basic survival, social and emotional experience.
Some of the most compelling evidence of early abstract thinking appears in the development of religious and mortuary practices. Inside the Neolithic Mind clearly expresses that certain powerful individuals managed complex systems of belief and practice. These early religious leaders weren't simply following traditions - they were actively managing complex symbolic systems that required sophisticated abstract thinking. They created multi-level models of reality, managed time-extended processes, and made abstract connections between visible and invisible realms. This represents one of the earliest documented examples of humans using their PFC to create and maintain complex systems of abstract thought. What's more, it indicates that much if not most of the tribes were by now accessing their PFC in more modestly refined ways.
Tool innovation provides another window into early abstract thinking. By about 50,000 years ago we see composite tools - those requiring multiple components and materials – which demonstrates the ability to hold complex mental models and plan multiple steps ahead. This is what only the mature PFC could do. While spear throwers had a smaller PFC, handled ax wielders had basically the same cortex we have today.
Navigation skills among early humans provide particularly compelling evidence of abstract thinking. Long-distance travel and trade required the ability to maintain mental maps, understand seasonal patterns, and communicate spatial information to others. The individuals who first developed these navigation systems were creating abstract representations of physical space that could be (theoretically) shared and taught.
The development of artistic expression, particularly cave paintings, represents another domain where early geniuses pushed cognitive boundaries. The artists who created works like those in Chauvet Cave (around 30,000 years ago) weren't simply depicting what they saw - they were creating sophisticated compositions that communicated complex ideas and experiences including a proclivity for animism. This required the ability to think symbolically and create representations that others could understand by means other than simple observation.
What makes these early innovations particularly remarkable is that they occurred during the period when humans were just beginning to utilize their PFC's capabilities for abstract thought. These weren't just clever solutions to immediate problems - they represented entirely new ways of thinking that had to be discovered, developed, and taught to others.
The legacy of these early pioneers extends far beyond their immediate innovations. By creating frameworks that others could follow, they established patterns of abstract thinking that would eventually lead to writing, mathematics, science, and philosophy. They were the first to venture into the cognitive territory made possible by our pre-adapted PFC, blazing trails that subsequent generations would follow and expand.
Their achievements demonstrate that genius isn't simply about having more knowledge - it's about being able to use existing neural capabilities in novel ways. These early geniuses were working with the same basic brain structure we have today, but they were the first to discover how to use it for abstract thought. In doing so, they began the ongoing process of human cognitive evolution that continues to accelerate in our own time.
The activation of latent cognitive capabilities during this period emerged from several converging factors. Population densities reached levels that created new social pressures and opportunities. These denser populations formed networks where information and innovation could spread more effectively initially via oral tradition then, ultimately, in writing, creating feedback loops of cognitive development.
The key development, as Mithen explains, was the transformation of language from purely social purposes to general-purpose communication: "Those individuals who could exploit these invasions to increase their own knowledge about the non-social world would have been at a selective advantage....These talkative individuals were gaining their selective advantage by exploiting the non-social knowledge of other individuals by using language, as opposed to relying on behavioral observations alone." (page 187)
This shift in language use represents a fundamental change in how humans were utilizing their neural architecture. The PFC, a evolution of upright posture and binocular vision, began to be accessed for abstract thought as language expanded beyond social purposes. This wasn't a biological evolution but a cultural one – more numerous humans learning to use neural capabilities that had been present but underutilized.
The increasing complexity of social relationships created environments where abstract thinking provided significant advantages. As groups grew larger and interactions became more complex, the ability to think abstractly about social relationships, alliances, and future possibilities became increasingly valuable. This social complexity created selective pressures favoring individuals who could access their prefrontal cortex's capabilities for abstract thought.
The archaeological record provides compelling evidence of this cognitive expansion. Tool-making became increasingly sophisticated, showing not just technical advancement but the ability to think abstractly about future needs and specific solutions. This represents clear engagement of the prefrontal cortex in planning and problem-solving at a level never seen before.
Cave art emerged as a powerful demonstration of new cognitive capabilities. These artistic expressions weren't simply decorative efforts but represented complex symbolic thinking - the ability to translate three-dimensional reality into two-dimensional representation, to understand and manipulate abstract symbols, and to communicate complex ideas through visual means. This required sophisticated integration of the prefrontal cortex with other brain regions, particularly those involved in visual processing and spatial understanding.
Long-distance trade networks from this period indicate the development of abstract thinking about time, space, and social relationships. These networks required the ability to conceptualize and maintain relationships across time and space - a clear indication of prefrontal cortex engagement in abstract planning and social cognition.
Complex burial practices provide particularly compelling evidence of abstract thought. As theorized in /Inside the Neolithic Mind/: "Neolithic people practiced serial burials for mythological and, importantly, cosmological reasons... Their view of the cosmos entailed multiple stages of post-mortem existence that were lived out in multiple cosmological levels." (page 79) This represents sophisticated abstract thinking about life, death, and cosmic order - concepts that require full engagement of the PFC's capabilities.
The transmission of these new cognitive capabilities relied heavily on exceptional individuals - early geniuses who could first access and utilize their prefrontal cortex in novel ways. These individuals weren't just passing on technical knowledge; they were creating frameworks that helped others access their own cognitive potential. But, this equally required the passage of time so that more people could access (go “online”) their PFC.
These early teachers and leaders developed ritual practices and traditions that served as cognitive scaffolding for the tribe. The complex burial practices mentioned earlier weren't just religious expressions but sophisticated teaching tools that helped people conceptualize abstract relationships and cosmic order. “powerful individuals” were likely among the first to fully utilize their PFC for abstract thought, creating pathways for others to (eventually, glacially) follow.
The cultural explosion thus represents humanity's first major step toward utilizing the pre-adaptive capabilities of the prefrontal cortex. Led by exceptional individuals who could first access these capabilities, human communities began developing frameworks that would eventually enable widespread abstract thinking. This period set the stage for all subsequent human cultural development, from the development of agriculture to the emergence of written language, from the steam engine to smartphones and brain implants.
Our current rationally based cognitive capabilities weren't directly selected for but emerged as we learned to use neural architecture that evolved for other reasons. It was a coincidental, astonishing alignment of brain regions. This has profound implications for our understanding of human potential - we are probably still in the early stages of learning to coordinate brain regions or maximize our PFC. The fourth astonishment is the most hopeful one of all.
(to be continued)
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