How Rational Are We? The Need to Better Understand the Nature of Human Intelligence

Introduction

How smart are we? Throughout this website I argue that humans are a unique kind of being: an intelligent life-form. That doesn’t mean we always have the right answers or make smart choices. It means that unlike other animals, our survival does not depend upon the physical capacities that are built into our organisms–claws, canines, wings, gills, etc. Rather, we rely on our ability to understand cause and effect: a level of intelligence that gives us the ability to use nature’s processes for our own ends.

We clearly are intelligent. The gains made by contemporary science—genetic engineering, hydrogen fusion, supercomputers, etc.—are truly cognitive marvels. Ironically, it is the incomparable powers that our intelligence has made possible that pose the greatest threat to our survival. We have been too successful. Our out-of-control growth process is taxing the carrying capacity of our planet. We are good at pushing the process forward, but we haven’t figured out how to bring it under control. The trade-offs that would involve are the true measure of rationality. And frankly, this is not rationality’s finest hour.

On top of climate-change denial, we have seen massive, conspiracy-fueled resistance to public health measures during the pandemic. Currently, in the USA, millions of literate, 21st century Homo sapiens have embraced bizarre narratives– Pizza Gate, QAnon, and the like. A sizeable slice of the public is prepared to accept any fantasy that appears to support their side in a political and culture war that is basically unconnected to the real problems facing humanity. And this lunacy is being stoked by a demagogue who has given the nation a crash course in denial and deceit.

All of this raises the question—how rational are we? During the 19th century, human intelligence was seen as an irrepressible force, a power that would inevitably give rise to a rational and more humane world. Today, however, faced with an ever-growing number of intractable problems and self-inflicted wounds, that opinion has fallen out of favor. Doubts about our rational powers are gaining strength and the future, as popular culture informs us, is almost universally seen as dystopian.

This disillusionment and loss of faith in our rational powers has to be concerning. Intelligence is our species’ ticket to the future: it’s how we survive. If we are not up to the mental challenges we face, we won’t have a future. As we know from personal experience, we humans are affected by what we think about ourselves. If humanity loses faith in its intellectual capacities, its ability to make the effort that the future requires will be severely compromised. An army that doesn’t believe it can win, has already lost.

Our species’ intelligence is undeniable. At the same time, a celebratory approach towards human rationality is not in order. We have an ample capacity for illusion, error, and plain old stupidity. Indeed, what is clear is that we are neither wholly rational nor wholly irrational. The question, then, should not be whether we are one or the other, but rather, whether it is possible to tilt the playing field—to create an environment that enhances our rational dimension. I believe it is, and it has to do with developing a greater awareness of how our minds work.

A Series of Essays

I have decided to break the discussion of human intelligence into a set of essays. It’s not an easy subject and is best digested in small bits. I begin with the problem of determining the relationship of human intelligence to that of our animal relatives. This is a critical issue for human evolutionists. It goes to the heart of what is distinctive about humanity. Surprisingly, there is no scientific consensus on this: just a lot of different opinions.

I find this gap in our knowledge deeply troubling. The problem here is that we don’t really know what intelligence is. Think about that. Clearly, our intelligence holds the key to our special relationship to the natural world. But we don’t know what it is or how it compares to that of the other creatures on this planet. Frankly, that gap bears testimony to how little we really know about our place in nature.
In this first essay, I tackle the problem of the distinctive nature of human intelligence. I end that discussion by bringing the analysis of our mental capacities up to date—by arguing that the very features that make our intelligence exceptional makes us vulnerable to the conspiracy theories and disinformation that currently plague us—that threaten to derail our efforts to focus human effort on the existential challenges we face.

The Distinctive Nature of Human Intelligence

My hypothesis about human evolution begins with difference–the conviction that there is something that radically distinguishes humans from the rest of the animal world. The key to understanding our place in nature, then, lies in discovering what that difference is and how it could have come about. The vast majority of human evolutionists don’t see things this way. They don’t believe humans are radically different from other animals. In their view, the fact we evolved from an animal is incontestable evidence of our continuity with other life-forms. And in this, they are following in Darwin’s footsteps.

Before Darwin, it was assumed there was an unbridgeable gap that separated humanity from the natural world. Darwin erased that gap. While he did not propose a specific model of human evolution, he uncovered the mechanisms of an evolutionary process that could account for all the varied life-forms found on our planet—including us. The implications of his discovery were clear: humans must have “descended” from a “lesser animal:” we are an inseparable part of the animal kingdom. That was a message humanity needed to hear at that stage of our development. But times change. Today, it is what makes us different—the disconnect between humanity and the rest of nature —that we need to understand. After all, it is what makes us different that has gotten us into all the trouble.

Efforts to determine what’s different about humans invariably end up focusing on intelligence. We clearly are smarter than other animals. The question, however, is by how much? Darwin believed our intelligence was on a continuum with that of the animal world. Yes, we are smarter, he argued, but the difference is one of degree rather than of kind. This position has a lot going for it. Our brains are much larger than those of other animals– three times larger than those of our great ape ancestors and seven times larger than those of the average mammal. Nevertheless, there is nothing in our neurological architecture that doesn’t have antecedents in the brains of other animals. Bigger—yes: but fundamentally different—no evidence. When we consider the latest experimental evidence about the intelligent behavior of other animals, the case for degree over kind would seem to be incontrovertible.

And yet, common sense would seem to suggest there is something importantly different about our intellectual faculties. There are two features in particular that lend weight to this assumption. The first is an issue that Darwin should have noticed—but didn’t. Our level of intelligence has placed us outside the sphere of Darwinian evolution. Darwin’s revolutionary discovery was natural selection—the process by which the biology of animals automatically adapt to the rigors of their environment. However, humans don’t adapt to their environment with their biology. Our intelligence enables us to adapt with cultural inventions–technologies, organizational forms and accumulated know-how. These unique capacities would seem to indicate that humans have passed over some cognitive threshold that distinguishes us from all other creatures on the planet.

The second critical distinction has to do with the different kinds of information that humans and animals can process. Even such intelligent animals as porpoises and chimpanzees cannot be taught a single fact about the decline and fall of the Roman Empire. The knowledge that animals can acquire is restricted to the perceptual information they can extract from direct, sensory experience. Humans, on the other hand, can synthesize information into abstract constructs. We can build mental models of things we have never directly experienced—like the Big Bang, distant galaxies, sub-atomic particles, and the fall of Rome.

What explains this difference? Does it simply represent a step on a continuum—or does it involve a leap to another plane?

Need for a Different Model of Intelligence

Part of developing a new relationship with nature involves changing the way we think. Just as humanity replaced a mythological imagination with logical and causal-based reasoning, we are going to have to develop new ways of making sense of a universe that doesn’t always behave according to our current expectations. During the 20th century, we learned that light, depending on the context, can exhibit the properties of either a wave or a particle. In the same vein, our intelligence can be seen to differ from that of animals by both degree and kind. In some ways, our cognition is clearly on a continuum with that of other animals. At the same time, there is a yawning gap, a discontinuity that separates our mental faculties from theirs. There is something missing in the way we understand human intelligence.

Currently, human cognition is viewed through a biological lens. It is traced to the functioning of a physical organ: the brain–something we are born with. If we see our intelligence as the expression of a biological-based capacity, then we must assume that it developed through an evolutionary process. This would appear to support the idea that it is on a continuum with animal intelligence. Evolution has an unavoidably gradual, continuous dimension. It involves the transformation of the biology of a community of animals (species). For any genetic change in an individual to be passed on it must be compatible with the biology (the reproductive system) of the other members of its community. If an individual mutation is too extreme, the offspring will either be inviable or sterile (like mules or tiglons). This would seem to suggest that the human brain must have evolved through a relatively continuous process and that a major discontinuous event would have been extremely improbable.

There is a different way of looking at human intelligence. But we must begin by abandoning the idea that that our intelligence is based wholly on a biological foundation. Human cognition, in fact, depends largely on a “tool:” an instrument that is independent of our biology–language. While the biology of our brain has been shaped to assimilate a language, nevertheless, a language must be learned. It is truly a tool: a kind of code we obtain from our external social environment. It consists of a set of symbols (words) and rules for combining them (grammar) that enable us to represent our thought processes in a form that can be read by others. However, it does much more than render our mental processes tangible.

language provides the brain with capacities that are not built into its natal endowment. A human level of intelligence is not a product of our biology alone. It is the result of a merger between biological processes and a cultural tool. The brain is indeed a biological organ, and it took shape through an evolutionary process. Its operations lie on a continuum with the brains of other animals. Like their brains, it is equipped to use sensory information (sight, sound, touch, and taste) to construct the world of images that we experience in perception. Language, however, adds to that capacity. It enables the brain to go beyond perception—beyond imagery. It allows it to construct abstract models of things. And this transforms human intelligence.

Language is Abstract

When we look around us, we see a world that is made up of objects. Our senses form images of these objects—trees, lawns, houses, dogs, etc. Those images are representations of real, individual things. It is generally assumed that words are simply labels we use to designate these objects. We see that thing over there and we tell our neighbor: “That’s a rock.” But is it a rock? Or is it a small, roundish, grey-colored, hard object? If we call it a rock, we are ignoring its individual, physical composition and are focusing instead on what it has in common with a set other things. Rock is a category.

Categorization is a fundamental feature of intelligence—not just human intelligence, but that of animals as well. In a world in which no two things are ever entirely identical, it is important for animals to find commonalities—general patterns that make the world recognizable and predictable. Animals form perceptual categories. They lump together objects and events that share certain critical physical or behavioral characteristics in common. A gazelle must know the difference between a cheetah and a lion. It must also know the common danger posed by a lion that has a mane and one that doesn’t. Humans also construct perceptual categories. However, we are capable of constructing a different kind of category; one that is not based primarily on perceptual information.

Perception—the information we get from our senses—enables us to recognize that all those skinny creatures that lack limbs, whether they are large or small, brown or multicolored, are fundamentally the same kind of creature. They should be put into the same category–snake. Beware of them. At the same time, our senses tell us a snake is very different from an alligator or a turtle. These animals neither look alike nor behave similarly. However, naturalists have discovered that in relationship to the animal world in general, these animals share certain important features in common. As a result, we have put them in the same category– reptile.

What does the word reptile mean? What does it refer to? The word does not refer to any real, tangible creature. There is no actual, existing reptile entity that we can see and touch. There are just individual snakes, alligators, turtles, etc. There is, then, nothing concrete the senses can use to form an image of reptile. Reptile is an abstract model that the mind constructs from certain features that are shared by snakes, alligators, turtles. Sounds good. But what is an abstract model? If we can’t experience something with our senses, how can we experience it at all? While we may not be able to form an image of reptile, we can think reptile. We have no problem with that. However, what we normally don’t realize is that we can’t think reptile without the word reptile.

Let’s perform a thought experiment. Try to think reptile without bringing the word to mind. The result is a series of images of different individual reptiles. Without the word reptile, the mind cannot rise above imagery—above images of different individual reptiles. Humans process information differently than other animals. We use language as a tool to create models of things that transcend the framework of the senses. (See addendum for more extended discussion of this)

Language does not, as is generally believed, translate already existing thoughts into something tangible. Rather, it enters into and re-organizes our mental processes. My favorite description of this was given by the Soviet psycho-linguist, Lev Vygotsky. He coined a term—“verbal thought”–to describe the peculiarities of human consciousness. Human mental operations, he proposed, are formed through a merger of language with our biologically-based cognitive processes. “Thought,” as he put it, “is not merely expressed in words; it comes into existence through them.”

Vygotsky’s clinic studied language acquisition in hundreds of children. He concluded that when children learn a language they are not simply memorizing a list of names; they are reorganizing their mental processes. They are encoding their perceptual world into terms that elevate their thinking to a higher level of generality. Words that refer to concrete, observable objects—rose, daisy, etc.—must be connected to and coordinated with a set of more abstract, inclusive terms, e.g., flower, plant, etc. It takes years, Vygotsky’s research established, for children to correctly sort out the different levels of generality involved in mastering a linguistically organized picture of the world.

The Social Nature of Human Intelligence

There is another critically important dimension in the relationship of language to human intelligence. I’m just going to touch on it in this essay.
Language gives rise to a collective consciousness. It gives humans access to each other’s mental processes and states of awareness. As you read these words, you are experiencing my thought processes. The capacity of language to connect the thinking of different individuals enables humans to pool knowledge from different people, times, and places. Every time we perform a math or engineering problem, we are making use of inventions that have come down to us from the beginnings of civilization—algebra (Egypt 1650 BCE), geometry (Greeks, 300 BCE), “Arabic” numerals (India 6th Century AD), etc., etc.

The ability to construct a collective body of knowledge is clearly one of our greatest assets. The greater part of what any human individual knows has been acquired from other people—from one’s community, one’s culture. How many of us know, from our own personal experience, that the Sun lies in the center of the Solar System: that our bodies are made of trillions of little cells: that continents drift: that germs cause disease: that we evolved from apes—or even that Omaha is in Nebraska.
Language accumulates, organizes, and makes the distribution of a vast reservoir of knowledge possible. We largely think with the models that others have constructed.

Every Strength is a Weakness

In this essay, I have attempted to demonstrate what a powerful asset language is. It is the primary factor that accounts for humanity’s dominant position in the biome of our planet. It carries our intelligence beyond the boundaries of the biological brain, placing us on a new, and unique path of cultural development. Nevertheless, it is not without its downside.

There is a contradiction that lies in the very core of language. On the one hand, it gives us the ability to construct abstract models and acquire information from others. These gifts immeasurably multiply our cognitive capacities and our knowledge base. At the same time, however, by extending our consciousness beyond the framework of the biological brain, language gives rise to an awareness that is not fully grounded in our own sensory experience. One may know a lot about germs, galaxies, sub-atomic particles, the length of the solar year, etc., but that knowledge is not derived from one’s own direct experience. It is based on constructs that come to us from other times, other places, and other people.

Our consciousness, then, is largely the result of a collective, historical process. Our view of the world is a construct that represents something of a cooperative, cultural consensus–the way a given community has come to make sense of its experience. In general, our access to a collective body of knowledge is immensely valuable and provides us with information that vastly exceeds that which we could acquire on our own. However, our dependence on knowledge that has been put together by others has its downside. It is not fully grounded in our own sensory experience. When traumatic or unexpected events take place, it can more or less rapidly fall apart.

I came of age in the USA during the 1960s, and I participated in and/or witnessed various different communities, both in the USA and throughout the world, go through transformative changes in their ways of thinking. The catchword of that era was revolution. While that word meant different things in different places, in the youth upsurge that I participated in, it referred primarily to radical changes in the way people thought. While the roots of much of this new thinking had been developing for some time, nevertheless, it grew into an engine of change almost overnight.

There is, I have come to believe, a tipping point—-a moment when social dislocation and dissatisfaction reach a level where old norms and ideas no longer resonate. At that point, people begin to look for new ways to make sense of events. They open up to new ideas. While there was much that was positive in the opening up process of the 1960s and 1970s (opposition to Vietnam war, racism, and inequality in general), at the same time, the breakdown of the old consensus and our dependence on the thinking of others revealed a dark side.

The rejection of the past, the failure to connect with our society’s collective experiences, left many activists without any solid grounding. They were susceptible to extreme and fanciful ideologies, many falling under the sway of demagogues, charlatans, and cult gurus of all stripes— “visionaries” who emanated conviction and certainty, and who provided simple, emotionally charged solutions. And no solution is simpler than to reduce complex problems to a battle against some malevolent enemy.

Frankly, this is the world that is growing up around us today. The irrationality of a QAnon movement, the bizarre conspiracy theories of Pizza Gate and Shape-shifters, the efforts to prosecute Dr. Fauci, election denial, etc., should be taken seriously. We have been here before. These over-the-top beliefs and behaviors are indicative of the rise of a dangerous, psycho-social process–of a search for certainty and security that has gone off the rails.

How can rationality prevail once the irrational has taken hold? That’s our task.

Conclusion: Degree or Kind?

At the beginning of this essay, I stated that human intelligence differs from that of other animals by both degree and kind. Recent advances in comparative neuroanatomy reveal that the basic architecture of the hominin brain (from Homo habilis through early Homo sapiens), in spite of its significantly larger size, was fundamentally the same as that of Australopithecus and our closest great ape relatives. Then, around 140,000 years ago, the shape of the brain of our Homo sapiens lineage began to undergo changes.

The most probable explanation for all of this, is that the hominin brain was essentially a scaled-up great ape brain (differed by degree) that reached a level (early Homo sapiens) where it could begin to work more effectively with symbols. This altered the selective calculus, favoring the development of a fully developed language capacity, and by 50,000 years ago, a new, linguistic-based intelligence came into being. A difference in degree enabled the evolving human brain to incorporate a cultural tool that gave rise to an intelligence that was different in kind.

Skepticism

One of implications of the analysis presented here is that with language, human consciousness is largely a social/historical construct. Our knowledge keeps accumulating. But as it accumulates, it changes. As we learn more about one thing, it affects the way understand something else. Human knowledge, then, is always incomplete. The upside of this is that there is always room to learn more. The downside is that we generally don’t know as much as we think we do. As a result, we often fail to foresee the consequences of our actions, and as a result, we stumble a lot–commit a lot of errors i.e., atomic energy, plastics, use of fossil fuel, etc.

The fallibility of our knowledge has given rise to a powerful skeptical current. However, we should distinguish between two kinds of skepticism: dogmatic skepticism and healthy skepticism. Dogmatic skepticism argues that because our knowledge can never be complete or perfect, truth is an chimera, a Will’o’the wisp that lies beyond our grasp. Knowledge is held to be nothing more than a narcissistic illusion. Dogmatic skepticism produces nothing but paralyzing doubt.

Healthy skepticism also recognizes the incompleteness of our knowledge, but while counseling prudence, it embraces progress. While our knowledge may never be perfect or complete, it is always capable of improvement. Healthy skepticism is a wise guide–keeping the mind open and rejecting all dogmas.

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