Every day, more than two billion children around the world go to school, in what is perhaps the largest collective experiment in the history of humanity. There they learn to read, forge their closest friendships, and build themselves as social beings. And at school, in a highly intense learning process, the brain is developed and transformed. However, neuroscience has crassly ignored this close link, remaining distanced from classrooms for years. Perhaps now is the prime time to establish a bridge between neuroscience and education.
The philosopher and educator John Bruer warned that this bridge connects distant worlds; what neuroscience considers relevant is not necessarily or usually pertinent to education. For example, understanding that a region of the parietal cortex is key to the numerical process can be important for neuroscience but doesn’t help a teacher to teach maths better.
In this effort, we must remain, more than ever, sceptical about the use of vague and imprecise scientific terms. I was once in a conference in which a supposed expert in neuroscience argued–as so many do today–that we should use the right hemisphere more. I raised my hand (the left one to be compliant …) and mentioned that even if I agreed that using the right hemisphere was useful, I simply did not know how to do it. Should I turn my head to the right to increase blood flow to the right hemisphere? His ‘neuro-expert’ response was that I should focus on drawing, colouring books and creative arts and forget about language. And then my question was, why didn’t he just say that straight out? I knew the answer. He was employing an artful yet useless metaphor. Referring to the brain and the hemispheres only served to appropriate the prestige of a scientific field for marketing purposes.
There is a long history of translating basic knowledge into applied science. One perspective maintains that science should produce a body of knowledge with the hope that some of it will eventually be useful for society’s needs. An alternative approach, coined by Donald Stokes as Pasteur’s quadrant, consists in finding a niche where basic and applied research meet.
In Stokes’s taxonomy, scientific knowledge is classified according to whether it searches for fundamental understanding or has immediate use for society. The atomic model by Niels Bohr, for example, is a case in which science chases after pure knowledge. On the other hand, Thomas Edison’s light bulb is an example that takes usage into account. Pasteur’s research on vaccination, according to Stokes, deals with both dimensions; in addition to resolving fundamental principles of microbiology, it gave a concrete solution to one of the most urgent medical problems of the age.
In this chapter we will try to navigate the waters of neuroscience, cognitive science and education along Pasteur’s quadrant, exploring fundamental aspects of brain function in the hope of contributing to the quality and efficacy of educational practice.
When we learn to read we discover that the shapes p, p, P,p, p and P are the same letter. We understand that the precise combination of a line segment and a curve, of the ‘| + ⊃’, makes up the P. The curve can be smaller, the line can be tilted and the curve can slightly cross it, but we know that these forms, which are never identical, represent the same letter. This is the visual part of reading, whose process we have already looked at. But there is another, more complicated action, which entails learning to pronounce it. Understanding that this visual object ‘p’ corresponds to an auditory object, the phoneme /p/.
Consonants are difficult to pronounce because we never hear them isolated; they are always accompanied by a vowel. That’s why the consonant ‘p’ is called ‘pee’. Naming it without the ‘ee’ that follows feels strange. Additionally, some consonants require complex morphologies of the vocal apparatus like the explosive union of the lips to produce the /p/ or the palate juncture needed to produce the /j/. Syllables, especially when they are comprised of a consonant and a vowel, like ‘pa’, are much easier to pronounce.*
In Spanish or Italian there is a precise correspondence between phonemes and letters, which makes decoding them fairly transparent. But in English and in French that doesn’t happen, and those who are learning to read have to decipher a less straightforward code that forces them to scan a few letters before they can know how to pronounce them.
The importance of the expressive component of reading is usually underestimated, in part, perhaps, because we can read in silence. But even if we are reading in a whisper, we advance more slowly when the words are harder to pronounce. Which is to say, we internally pronounce the text we are reading even when we produce no sound.
Therefore, those who are learning to read are also discovering how to speak and how to listen. When pronouncing the word ‘Paris’ we produce a continuous stream of sound.* Asking someone who doesn’t know how to read to divide the word into /p/ /a/ /r/ /i/ /s/ is like trying to separate a ball of used, mixed Play-Doh into its pure original colours. Impossible. The syllables, and not the phonemes, are the natural building blocks of the sounds of words. As such, without having learned to read it is very hard to answer the question of what happens if we take the ‘P’ off the word ‘Paris’. This ability to break up the sound of a word into the phonemes that comprise it is called phonological awareness and is not innate but rather acquired along with reading.
Reading trains phonological awareness because in order to recognize a phoneme as a building block of speech it has to have a label, a name that distinguishes it and turns it into an object within that stream of sound. These labels are precisely what make up the letters that a phoneme represents. Therefore, an essential part of reading is discovering phonemes. In fact, most reading difficulties are not visual but auditory and phonological. Ignoring the phonological aspect of reading is one of the most frequent misperceptions in teaching.
Dyslexia is perhaps the most paradigmatic example of how neuroscience can be useful to education. First of all, research on the brain has helped us to understand that dyslexia has little to do with motivation and intelligence, but rather is the result of a specific difficulty in the cerebral regions that connect vision with phonology. The fact that dyslexia has a biological component doesn’t mean that it cannot be improved or reversed. It is not a stigma. Quite the opposite: it allows us to understand an inherent difficulty that a child may have when learning to read.
Another typical error is thinking that the problem of dyslexia is in the eyes, when the greatest difficulty is usually in recognizing and pronouncing the phonemes; in other words, in the world of sounds. This discovery opens the door to simple and effective activities for improving dyslexia. The way to help dyslexic children is often not by working with their vision but rather by helping them to develop phonological awareness. Having them listen to and pick up on the differences between ‘paris, aris, paris, aris …’ for example. In fact, this game of deleting a phoneme from a word is an excellent reading exercise: ‘Starling, staring, string, sting, sing-sin-in-I.’
Neuroscience can also help to recognize dyslexia before it is too late. Sometimes it only becomes obvious that a child is having a specific difficulty with reading after valuable months or years of his or her educational experience have already passed. With dyslexia, as in many other realms of medicine, early detection can radically change the prognosis. But the same medical analogy works to warn of the obvious, that this is a very delicate subject which requires special care and prudence. There is a clear advantage to early diagnosis, but the risk of stigmatization and self-fulfilling prophecy is also evident.
This decision becomes particularly hard because dyslexia cannot be predicted with certainty; we can only infer a predisposition to it. Let’s look for a moment at a more concise example, congenital deafness. Without mediating science, deafness is diagnosed later because during the first few months of a baby’s life the fact that they don’t respond to sounds goes unnoticed. With early detection, however, the baby’s parents can start to use a gestural, symbolic language and essentially a deaf baby will grow up better able to communicate. That child’s world will be less wide and strange. In fact, medical practice has already radically changed to recognize this awareness of the importance of early diagnosis. Soon after birth, babies are given an acoustic test that indicates whether they have an auditory dysfunction. With an early diagnosis of possible deafness, parents can be attentive to those aspects and improve their children’s social development. Something similar happens with dyslexia: the cerebral response to phonemes–at one year old–is indicative of the difficulties babies might encounter almost four years later, when they begin learning to read.
The subject is so sensitive and delicate that it is tempting simply to turn a blind eye to it. But ignoring this information is also a way of deciding. Decisions made by default–by not doing anything–might feel easier to make but do not side-step the need to take responsibility. One thing is for sure, a near future in which we will be able to estimate the likelihood that a child will develop dyslexia is imminent. What we must decide–at all levels of society, from parents, to teachers and head teachers, to policy makers–is how to act on this information. And this of course is a decision that goes beyond the scope of science.
My opinion is that information about the likelihood of dyslexia can be used carefully and respectfully, without stigmatizing children. It is good for parents and educators to know if a child has a significant probability of having difficulties in reading. This will allow them to give the child the opportunity to do some phonological exercises (which are completely innocuous and even entertaining) that might help in overcoming that initial disadvantage, in order to learn how to read, so that they have better prospects when starting the first year of school, with the same possibilities as the rest of their classmates.
To sum up:
(1) Phonological awareness, which has to do with sound and not sight, is a fundamental building block of reading.
(2) There is much initial variation in that ability–before starting to read, many children already have a configuration of their auditory system that naturally separates phonemes, while others have them more mixed up. Children who have low resolution in their phonological systems show a predisposition for dyslexia.
(3) With harmless and fun activities, like simple word games, the phonological awareness system can be stimulated before reading begins, at two or three years old, so that those children don’t start to learn to read facing a disadvantage.
The study of reading development is one of the most prominent cases of the way in which investigation of the human brain can be useful to educational practice. It is at the core of this book’s intention to explore how this reflective exercise on the part of science can help us to understand ourselves and communicate better.
Socrates questioned what common sense suggests, that learning consists of acquiring new knowledge. Instead, he proposed that it involved reorganizing and recalling knowledge we already have. I now put forth an even more radical hypothesis of learning understood as a process of editing, as opposed to writing. Sometimes, learning is losing knowledge. Learning is also forgetting. Erasing things that take up space uselessly and others that, even worse, are a hindrance to effective thought.
Young children usually write some backwards letters. Sometimes they even write a word or an entire sentence as if in a mirror. Compared to other ‘mistakes’ that children make when learning, this one is often overlooked, like some sort of endearing temporary clumsiness. But actually it is an extraordinary feat. First of all, because the children were never taught to write backwards. They learned it on their own. Secondly, because mirror writing is very difficult. In fact, just try to write an entire sentence backwards, the way kids do naturally.
Why does the development of writing have this peculiar trajectory? What does this teach us about how our brain works? The visual system converts light and shadow into objects. But since objects turn and rotate, the visual system is not very interested in their particular orientation. A coffee mug is the same turned backwards. Almost the only exceptions to this rule are certain cultural inventions: letters. The mirror reflection of ‘p’ is no longer a ‘p’ but a ‘q.’ And if we reflect it upside down it becomes a ‘d’ and then left to right again it turns into a ‘b’. Four mirrors, four different letters. Alphabets inherit the same fragments and segments of the visual world, but their symmetry is an exception. The reflection of a letter is not the same letter. That is atypical and unnatural for our visual system.
In fact, we have a very poor memory for the particular configurations of objects. For example, almost everyone remembers that the Statue of Liberty is in New York, that it is somewhat greenish, that it has a crown and one hand raised with a torch. But is the torch hand the left or the right? Most people can’t remember which it is, and those who think they do are often wrong. And which way is the Mona Lisa’s gaze directed?
It makes sense that we forget those particular details, since our visual system has to actively ignore these differences in order to identify that all the rotations, reflections and shifts of an object are still the same object.* The human visual system developed a function that distinguishes us from Funes the Memorious and makes us understand that a dog seen in profile and a dog seen head on are the same dog. This highly effective circuit is ancestral. It worked in the brain long before schools and alphabets existed. It was later in the history of humanity that alphabets appeared, imposing a cultural convention that goes against the grain of our visual system’s natural functioning. According to this convention, ‘p’ and ‘q’ are two different things.
Those who are learning to read still function with a default setting in their visual systems, in which the ‘p’ is equal to the ‘q’. Therefore they are naturally confused both in reading and in writing. And part of the process of learning implies uprooting a predisposition, eradicating a vice. We have already seen that the brain is not a tabula rasa where new knowledge is written. And as we just saw in the case of reading, some spontaneous forms of functioning can result in idiosyncratic difficulties in learning.
From the day we are born the brain already forms sophisticated conceptual constructions, like the notion of numerosity, and even morality. We root our reconstruction of reality in those conceptual boxes. When we listen to a story, we don’t record it word by word but rather we reconstruct it in the language of our own thoughts. That is why people emerge from the same cinema with different stories. We are the scriptwriters, directors and editors of the plot of our own reality.
This is highly pertinent in the educational environment. The same thing that happens with a film occurs with a class; each student reconstructs it in their own language. Our learning process is a sort of convergence point between what is presented to us and our predisposition for assimilating it. The brain is not a blank page on which things are written, but rather a rough surface on which some shapes fit well and others don’t. That is a better metaphor of learning. A problem of congruity, of matching.
One of the most exquisite examples is the representation of the world itself. The Greek cognitive psychologist Stella Vosniadou studied thousands and thousands of drawings in detail to reveal how children’s representations of the world change. At some point in their educational history, children are presented with an absurd idea: the world is round. The idea is ridiculous, of course, because all factual evidence accumulated over the course of their lives points to the opposite.*
In order to understand that the world is round one must unlearn something very natural based on sensory experience: the world is clearly flat. And when we understand that the world is round, other problems begin. Why don’t people in China, on the other side of the world, fall off? Here gravity starts to do its job, keeping everybody stuck to the earth. But this in turn brings new problems; why doesn’t the world fall if it is just floating in space?
The conceptual revolutions we experience throughout our life emulate, to a certain extent, the development of culture in history. The children who are shocked when they hear that the world is round are replicating the conceptual struggle of Queen Isabella when Columbus suggested his voyage to her.* So the problem of the earth floating in the middle of nothing is resolved in young infancy as it was so many times in the long history of human culture, resorting to giant turtles or elephants that hold it up. Beyond the fable, what is interesting is how each individual has to find solutions to resolve a construction of reality according to the conceptual framework in which they find themselves. An expert physicist can understand that the world is spinning, that it has inertia, that in reality it is in an orbital motion, but an eight-year-old cannot solve the dilemma of why the world doesn’t fall with the arguments in a child’s arsenal.
For classroom teachers, parents or friends, it is very useful to know that those who are learning assimilate information in a very different conceptual framework from their own. Pedagogy becomes much more effective when that is understood. It is not about just speaking more simply but rather about translating what you know into another language, another way of thinking. That is why, paradoxically, sometimes teaching improves when the teacher is another student who shares the same conceptual framework. At other times, the best translators are the students themselves.
The mathematicians Fernando Chorny, Pablo Coll and Laura Pezzatti and I did an extremely simple test, but which may have important consequences for educational practice. We put a mathematical problem to hundreds of students who were preparing for an exam in an entry-level course after dividing them into two groups. The first group was simply asked to solve the problem, just as with any other test. The second group was asked first to rewrite the formulation of the question in their own words and only then to solve the problem.
From one perspective, the extra task for the second group was a distraction that meant they had less time and concentration. But from the perspective that we sketched out here, it pushed them to do something key to learning: translating that formulation into their own language before solving it.* The change was spectacular; the performance of those who rewrote the problem improved almost 100 per cent over those who directly solved the problem as we had put it forth.
Now we will look at the world of geometry from the perspective of a child in order to discover that the process of rewriting concepts in one’s own language goes far beyond the world of words. In fact, it is enough to read the definition of parallelism to understand that geometry doesn’t get along well with words: ‘Equidistant from another line or plane, so that no matter how long they extend, they cannot intersect.’ The definition is filled with abstract terms: line, plane, equidistant (often the concept of infinity is used to define it as well). The word itself–‘parallel’–is complex to pronounce. Who would take to something like that? Yet, when we see two lines that are not parallel among several that are, they immediately pop out at us. Our visual system establishes intuitions that allow us to recognize geometric concepts long before they are put into words.
Three-year-olds can already distinguish two non-parallel lines among many parallel ones. Perhaps they can’t explain the concept, much less name it, but they understand that there is something that makes those lines different. The same thing happens with many other geometrical concepts, the right angle, closed or open figures, the number of sides on a figure, symmetry, etc.
There are two natural ways to investigate universal aspects that are not established by education. One is by observing children before they have been overly affected by culture and the other is by travelling to places where education is very different, as a sort of anthropologist of thought.
One of the most studied cultures for investigating mathematical thought is that of the Munduruku tribe, deep in the Brazilian Amazon. The Munduruku have a very rich, ancient culture, with very different mathematical ideas from those we inherited from the Greeks and Arabs. For example, they don’t have words for most numbers. There is a composite word to refer to one (pug ma), another for two (xepxep), another for three (ebapug), another for four (ebadipdip), and that’s it. Then they have words that represent approximate amounts, like pug pogbi (a fistful), adesu (some) and ade ma (quite a few). In other words, they have a mathematical language that is more approximate than exact. Their language can distinguish between many and few but not determine nine minus two is seven, which is inexpressible. Seven, thirty and fifteen do not exist in the Munduruku language.
Nor is their language rich in abstract geometrical terms. Does that mean that geometric intuitions in the Munduruku communities are very different from those in Boston? The answer is no. The psychologist Elizabeth Spelke discovered that when geometric problems are expressed visually and without using language, Munduruku children and kids from Boston solved them with very similar results. What’s more, the things that are simple for a kid from Boston–like recognizing right angles among other angles–are also easy for a Munduruku. Harder things–like recognizing symmetrical elements among non-symmetrical ones–are difficult for both groups of children.
Mathematical intuitions cut across all cultures and are expressed from infancy. Mathematics is built on intuitions about what we see: the big, the small, the distant, the curved, the straight; and about space and movement. In almost all cultures, numbers are expressed in a line. Adding is moving along that line (typically towards the right) and subtracting is doing the same thing in the other direction. Many of these intuitions are innate and develop spontaneously, without the need for any formal instruction. Later, of course, formal education is added on top of that body of already formed intuitions.
When comparing adults in Boston with Mundurukus, the former solved geometric problems much more effectively. This is almost stating the obvious, merely corroborating the fact that, if someone spends years studying a trade, they get better at it. But what’s most interesting and revealing is that while education improves our ability to solve all the problems, there is still a hierarchy of difficulty. The problems that are most difficult for us as adults are the ones that were impossible when we were children.
To sum up, when people discover something, they analyse it according to their own conceptual framework, which is built from very early (maybe even innate) intuitions. Through time and learning we go through conceptual revolutions that change the way in which we organize concepts and represent the world. But old intuitive conceptions persist. And we can trace that childish way of solving problems through adulthood, even in proficient experts considered to be great thinkers in their field. Problems that are not very intuitive remain tedious and hard to solve throughout our educational formation. Understanding how this body of intuitions works within the human mind is one natural route to improve the way we teach our children.
Earlier, I described learning as a process that transfers reasoning to the visual cortex of the brain in order to make it parallel, fast and efficient. Now we will look at the inverse process by which we acquire symbols that can describe innate visual intuitions.
Liz Spelke, Cecilia Calero and I studied how geometric intuitions turn into rules and words. Our theory was that the acquisition of knowledge has two stages. The first is a hunch; the body knows the response but cannot express it in words. Only in a second stage do the reasons become explicit as rules that can be described to ourselves and others. We also had another theory, conceived in the desert of Atacama, where Susan Goldin-Meadow, one of the great researchers of human cognitive development, told us about an extraordinary discovery she made after re-examining an old exercise done by Jean Piaget.
In the Swiss psychologist’s experiment, children were shown two rows of stones and had to choose which one had more. The trick was that while both rows had the same number of stones, in one of them they were more spaced out. The six-year-olds, driven by a ubiquitous intuition in our thinking, confused length with quantity and systematically chose the longer row.
Susan made a subtle but very important discovery about this classic experiment. While all the children answered that there were more stones in the longer row, there were remarkable differences in how they gestured their response. Some extended their arms to show that one row was much longer than the other. Other children moved their hands to establish a correspondence between the stones in each row. Those children, who were counting with their hands, had in fact discovered the essence of the problem. They weren’t able to express that knowledge with words, but their body language did. For that second group of children, the Socratic dialogue would work. The teacher only has to give them a little push to help them express the knowledge they already have. This finding is not a mere intellectual curiosity; when educators apply this information, their teaching becomes much more effective.
By this careful observation, Susan discovered that gestures and words tell different stories. We then decided to explore how the children expressed their geometric knowledge along three different channels: their choices, their explanations and their gestures.
In our experiment, the children were asked to choose the odd man out among six cards, the only one that didn’t share a geometric property with the others. For example, five of the cards had two parallel lines drawn on them and the other had two oblique lines in the shape of a V. More than half of the children under four years of age chose the only card that showed non-parallel lines. The others chose wrongly, but not randomly.
Some chose the card that had the most space between the two lines. Or the one in which the lines were the longest. They were focusing on an irrelevant aspect of the problem. Most of those children explained their choice in a consistent way, using words that referred to size. Their actions were coherent with their words. However, their hands told a completely different story. They moved them to form a wedge shape and then in parallel. Which is to say, their hands clearly expressed that they had discovered the pertinent geometric rule. Let’s just say that if it were an exam, their spoken answer would have failed them, but if they were scored on their hands they’d have passed.
We do not know yet the brain mechanisms that explain why information about geometry may be expressed through gestures or choice but not through language. Or what exactly happens in the brain in the moment in which children can have a more consistent grasp of these geometric intuitions and are able to express them in words.
But the experiments in which knowledge is measured through words, actions and gestures help us understand how we learn to forge concepts. Some concepts, like shape, form part of a core set of intuitions that are accessible to implicit knowledge and only later in development can be conveyed explicitly. Younger children can easily identify an odd shape even when they cannot express (to others and probably also to themselves) the geometric reasoning that justifies these choices.
The development of other geometric concepts, such as angles, follows a different path. They are first expressed through gestures at a time in which children cannot use this information for solving specific problems or for describing these concepts in words.
Why different concepts build up differently may be due to our innate biological predisposition, but most certainly, as well, they are due to how we relate to geometry in schools and homes. Most children grow up playing frequently with shapes, but have very little practical experience with angles, a dimension that can be much more naturally expressed by gestures. Above and beyond this, the more general point is that there are different precursors that serve to consolidate explicit knowledge.
Cecilia’s study showed how rudimentary children are when they have to express geometrical concepts with words. And in fact it’s not just children that this is true for. The Menon dialogue, which I described at the beginning of Chapter 5, shows that it’s also the case for adults. Developing notions of geometry is different from many other concepts such as number or theory of mind, because geometrical concepts aren’t composed in the same way that numerical and mental state concepts are. This is why it may be so hard for children and adults to express them verbally or learn them from others’ verbal expressions.
And here is where the real pertinence of these results for educational practice becomes evident. First, they suggest that geometry (and many other concepts) may not be taught well using words. This might be the essence of the failure of the Menon dialogue. Second, they also tell a teacher that language may not be a good vehicle to inquire about students’ knowledge of these matters.
The body is a consortium of expressions. Our words represent only a small fragment of what we know. And they are incredibly effective in conveying certain concepts and quite clumsy in expressing others. This may seem trivial in other domains. Imagine a football player being examined through a verbal description of how to take a free kick. As absurd as this may seem, it may be, to some extent, what we do with millions of children when we ask them to explain in words what they know about geometry.
Luis Pescetti, an Argentinian novelist, musician and actor, wrote a song in which a parent asks a teenage son a long series of questions. They all have the same responses: yes and no. This, of course, doesn’t mean that the son has no replies to the questions; just that he doesn’t want to answer. The song touches on an important lesson for developmental science: the best way to discover a teenager’s or a child’s inner thoughts is not through direct questioning, not in real life and not in the realm of scientific experimentation.
By exploring various procedures for investigating what children know, we found that the best way was not to ask anything but just to let them speak. This reveals an important principle of social beings: nothing has meaning in and of itself, but, rather, meaning is acquired when someone can share it. The need to share and communicate is a very natural predisposition.
What began as a technical resource for investigating explicit knowledge became something much more interesting, since we discovered that children have a sort of teaching instinct. They are natural teachers. A child with any sort of knowledge has a very strong propensity to share it.
Antonio Battro studied with Piaget in Geneva in 1967. Over time he became the standard-bearer of technological transformation in the classrooms of Nicaragua, Uruguay, Peru and Ethiopia. Just as we were exploring children’s innate desire to share their knowledge, Antonio came to our laboratory in Buenos Aires with an idea that was to transform our work, protesting that it was absurd that all neuroscience was dedicated to studying how the brain learns while completely ignoring how it teaches. And he argued that this was particularly strange because the ability to teach is one of the things that distinguishes us as a species, that makes us human. It is the seed of all culture.
We share the capacity to learn with all other animals, including the Caenorhabditis elegans, a worm less than a millimetre long, and the Aplysia sea slug, with which the Nobel laureate Eric Kandel discovered the molecular and cellular mechanics of memory. But we have something distinctive and particular that takes this ability and both communicates and propagates knowledge; those who have learned something have the capacity to transmit it. It is not a passive process of assimilating knowledge. Culture travels like a highly contagious virus.
Our hypothesis was that this voracity to share knowledge is an innate compulsion, like drinking, eating or seeking pleasure. To be more precise, it is a programme that develops naturally, with no need to be taught or explicitly trained. We all teach, even when no one has ever taught us how. Just as Noam Chomsky suggested we have an instinct for language, my colleague and friend Sidney Strauss and I emulated his idea and proposed that we all have a teaching instinct. The brain is predisposed to spread and share knowledge. This hypothesis is built upon two premises.
Long before learning to speak, children communicate. They cry, they request, they demand. But do they communicate information with the sole objective of remedying a gap in knowledge? Do they teach before starting to talk?
Ulf Liszkowski and Michael Tomasello came up with an ingenious game to answer these questions. An actor let an object fall off a table in full view of a one-year-old child. The scene was composed in such a way that the children saw where it fell but the actor didn’t. Later, the actor diligently and fruitlessly searched for the object. The little ones spontaneously acted as if they recognized this gap in knowledge and wished to remedy it. And they did so with the only resource available to them (since they could not yet speak), which was by pointing to the location of the object. This could be merely automatism. But the most revealing element of this experiment was that, if it was made clear in the staging that the actor knew where the object had fallen, then the one-year-olds would no longer point to it.
This is almost pedagogy, in that:
In some sense, the one-year-olds have an economic perspective of knowledge; that is to say, the effort of transmitting it is only worthwhile when it is useful to the other person.
What their action lacks to make it fully teaching is for the transmission of knowledge to empower the student to continue on their own. In this case, the baby shows the actor where the object has fallen, but–ungenerously–doesn’t show them how to find it when it falls again.
Before learning to speak, children can also proactively intervene by warning an actor when they anticipate their making a mistake. Which is to say, they try to close the communication gap even when dealing with actions they presuppose will happen but which have yet to occur. This ability to foresee others’ actions and act accordingly is at the core of teaching and is expressed even before a baby starts to talk and walk.
No one taught us to teach as children. We obviously didn’t go to teachers’ college or pedagogical workshops. But if we indeed possess an innate teaching instinct, we should teach naturally and effectively. At least as children, before that instinct atrophies. Here we see a problem: the teaching quality depends on how much the teacher knows about the topic. To know whether children communicate effectively, independent of their specific knowledge about the subject, we have to observe their gestures, not their words. Here, what is not said is more important than what is.
There are universal aspects to human communication. Beyond words, semantics and content, one of the virtues of effective speeches–like those of the great leaders in history–is that they work on an ostensive level. Ostensive communication is a concept that has been visited and revisited by philologists and semiologists like Ludwig Wittgenstein and Umberto Eco. It refers to the ability to use gestures to amplify the speech and use as few words as possible. It uses an implicit key that is shared between the speaker and the interlocutor. If we lift one hand with a salt shaker in it and ask someone: ‘Want some?’, there is no need to be explicit about what we are offering them. It’s the salt. This is a precise dance of gestures and words that happens in a fraction of a second without us even knowing that we are dancing. A robot versed in language would have asked: ‘Excuse me, what is it you are asking me whether I want some?’
The key to this method of communication is pointing. When we say: ‘That one’, and point, others understand what those words and that hand are indicating. It is a highly efficient way of communicating. Monkeys, who are able to do a countless number of sophisticated things, don’t understand this code that is so simple for us. It is a way of relating to each other that defines us, that makes us who we are.
By adorning our speech with prosody, gestures and signs, ‘ostensive communication’ also serves to label and parse out relevant moments of discourse. With this, the emitter ensures that the listener does not get distracted during the essential part of a message, which would result in a major communication failure.
Ostensive keys are easily recognizable. One is looking into the other person’s eyes and directing one’s body towards them. Aiming one’s gaze or body at the listener functions as a magnet for their attention. Other ostensive cues are using the receiver’s name, lifting our eyebrows or changing our tone of voice. These all make up a system of gestures, which we recognize as natural but that were never taught to us, and that determine the efficiency with which a message is communicated. Perhaps the most spectacular demonstration of how gestures come naturally without needing to be taught is that they are used by the congenitally blind even when in many cases they have never perceived them through other sensory modalities. We can think of it as a channel of communication. The transmission of the message is effective if we tune that channel in well, and it becomes static-y, confused or ineffective if we don’t find the exact frequency of this natural channel of human communication.
Two Hungarian researchers, Gergely Csibra and György Gergely,* discovered that the ostensive channel of human communication is effective from the very day we are born. Newborns not only learn more when we communicate while looking at them, changing our tone of voice, calling them by their name or pointing at relevant objects. They also learn in a completely different way.
When a message is communicated ostensively, the receiver understands that what they’ve learned goes beyond the particular case that is shown. When we tell babies without ostension that an object is a pencil, they understand it as a description of a particular object. Yet when we say the same thing with ostensive cues, they grasp that this explanation refers to a whole class of things that this object in particular belongs to.
When a message is communicated ostensively, receivers also assume that what they’ve been shown is complete, that the class is over. In an experiment illustrating this, a teacher shows children one of the many uses of a toy. In one case, this demonstration is carried out ostensively, with a gesture to finish that clearly indicates that the show is over. In the other case, after the demonstration, the teacher abruptly leaves the room.
In both cases the children were taught exactly the same thing, but their responses are very different. In the first case, the children do not explore other uses of the toy, denoting that they understand that the lesson was complete. In the second case, they spontaneously explore the toy’s other functions, showing that they understand that they were explained only some of its uses.
At six years old, children make highly precise evaluations, based on ostensive cues, of the quality of the information they receive from a teacher. When they have reasons to doubt a teacher’s reliability–for example, because of lack of ostension–they investigate beyond what they’ve been taught. So learning not only depends on the content of the message but also on the reliability of the person communicating it. This also reveals a paradox in education: good teachers transmit completeness and with this they inhibit their students’ further exploration.
Gergely and Csibra gave this implicit code for sharing and assimilating information the designation ‘natural pedagogy’. In other words, ostension is a natural and innate way of comprehending what is pertinent and relevant. This makes it possible to discover rules in a world of information as vast and as ambiguous as ours. Herein lies something essential to human intuition and comprehension, something that is very difficult to emulate and that explains the seemingly clumsy learning abilities of the automatons we design.
This survey of the fundamentals of human communication will now allow us to tackle the question we sketched out earlier. In order to know whether children are objectively good teachers, all we need to ask ourselves is whether they are ostensive, whether when communicating something important they lift their eyebrows, use the receiver’s name, and direct their body towards them, using the entire arsenal of ostensive cues that will make the receiver pay attention and feel that the information transmitted is complete and reliable. And this is independent of whether or not what’s transmitted is correct, which depends on how much they know about the subject and not how well they teach. It is a precise and implicit way of asking if they have well-formed intuitions about the effective channels of human communication. The path was left clear but we still needed to walk down it. Which is what we set forth to do with Cecilia Calero.
Our project involved a relatively simple arrangement, whose originality consisted in putting children in the place of the teachers. A child learned something, like a game, a mathematical concept, a universe with its own rules, or fragments of a new language. Then another person, who lacked that knowledge, would arrive on the scene. And from there we began to observe. In some cases we studied the children’s propensity to teach the new arrivals. In others, the newcomers would ask for help, and we studied what, how and how much the child taught them.
We discovered that the children naturally taught with enthusiasm and loquacity. They smiled and enjoyed teaching. In the hundreds of activities that Cecilia did, there were many times when the children wanted to interrupt–and did–while they were learning. But there was not a single child who didn’t want to teach.
During the class that the child gave the newcomer, there were moments of varying pertinence. Some were irrelevant to the exchange. For example, there was the boy who talked about his sister, that it was raining, or hot–weather is maybe the only topic we are comfortable talking about with any stranger, at any time, anywhere in the world. And other times one would transmit content relevant to the game they wanted to teach, such as its logic or strategy. And right at that moment the child teacher began using a barrage of ostensive cues. That display of gestures denoted that the child knew how to teach in order to gain the attention of the learner’s more sensitive channels.
The list of ostensive cues included eye contact, lifting their eyebrows, pointing or referencing an object in space, and changing their tone of voice. And then Cecilia discovered another unexpected factor. We saw that the children, when they taught, would move around and get out of their chairs. We, from our place as researchers, would ask them to sit down to avoid distractions that would make it harder for us to detect their ostensive gestures. And, as we only realized later, that led us to miss the chance to make a discovery. When we didn’t try to maintain order and we just let things follow their natural course, we discovered that the children, invariably, would stand up when they were teaching. Not one of them was sitting. They would get up and start moving around. We still have to discern whether that has to do with an ostensive gesture to mark the flow of knowledge; in other words: ‘I am standing because I am the one who knows,’ or if, rather, it’s related to a question of irrepressible excitement caused by the rush of teaching.
In one of the experiments that Cecilia did, the children–between two and seven years old–had to teach an adult a very simple rule. A monkey was smelling flowers, and they had to find out which ones made the monkey sneeze. The only difficulty was that the flowers weren’t always presented one by one so the game involved some deductive reasoning. But the game was simple enough for a two-year-old to easily solve it. After that, an adult would come and solve it incorrectly. The children thought that this was very funny. In fact, feigning incomprehension is a typical game between adults and children.
Most of the children responded by teaching the adult the tools needed to solve the problem. But a few of them said something like this: ‘When they show you a flower, look at me. If it’s the one that makes the monkey sneeze, I’ll wink. And if it isn’t, I’ll lift my eyebrow.’ They were cheating by offering to tell them the answer. On one hand, this shows the origins of this kind of copying in a school setting. But it also suggests something profound and central to teaching. Teachers of all types have to stop the class they are teaching from time to time if they feel that the students are not prepared for it. Where, when and how to do that is one of the most delicate problems in pedagogy. In a way, those seven-year-olds solved it by proposing a solution based on trick signals instead of explaining it. This suggests that if adults were incapable of doing something so simple, the children felt it was not worth trying to teach them, so they abandoned the pedagogy.*
Through exploring when and what we teach, we discovered that in infancy we were voracious, enthusiastic and effective teachers. But we still have to answer the toughest question: why do we teach? Why do we invest time and effort in sharing our knowledge with others? The why behind human behaviour almost always raises countless questions and unexamined answers.
Let’s look at an apparently much simpler example: why do we drink water? We can give a utilitarian response: the body needs water in order to function. But no one drinks water because they understand that premise; we do it because we are thirsty. But, then, why do we get thirsty? Where does that desire to get up and seek out water come from? We can propose a reply from a biological perspective; in the brain there is a circuit which, when it detects that the body is dehydrated, links the motivation engine (dopamine) with water. But this only shifts the question: why do we have that circuit? And this avalanche of questions always ends in an argument about evolutionary history. If that mechanism weren’t there and we didn’t feel the desire to drink when our bodies lacked water, we would die of thirst. And, therefore, we wouldn’t be here today, asking these questions.
But a system forged in the evolutionary kitchen is neither precise nor perfect. We like some things that are bad for us and we dislike some things that are good for us. Besides, the context changes, so that the same circuits that were functional at one point in evolutionary history cease to be so in another. For example, eating past the necessary levels could be adaptive to stockpile calories in a period of shortage. But the same mechanism is harmful and becomes the driving force of addictions and obesity when there is, as often happens today, a larder filled with food. Thus a reasonable premise for understanding the genesis of the cerebral circuits that make us do what we do and be who we are is that in some contexts–not necessarily the current one–it was adaptive. It is an evolutionary view of the history of biological development.
These arguments can also be proposed, although not as firmly, to understand the propensity to behaviours that forge social being and culture. In this case–why it may be or may have been adaptive to teach–we can sketch out the following argument, which is best located in a simpler time than contemporary society: teaching other people to defend themselves from a predator is a way of protecting oneself. In the jungle, many non-human primates have a rudimentary language based on calls that warn of different dangers, such as snakes, eagles, big cats. Each danger has a different call. We can think of this as something analogous to the prelude to teaching in babies, an argumentum ornitologicum: a bird in a privileged position to see something that others do not will share that knowledge in a public message (a tweet). The fact that every bird has this instinct results in a collective alarm system that functions very well for the flock as a whole.
Sharing knowledge can be detrimental to the one who shares it (which in commercial terms is the reason behind all patents and the secret formula for Coca-Cola, for example). But we understand that, in many circumstances, disseminating information can create groups with resources that confer an advantage on the individuals who make up that group. These are, generally, the typical arguments for understanding the evolution of altruistic behaviours and a utilitarian reason for understanding the genesis of human communication. Teaching others is a way of taking care of ourselves.
The propensity to share knowledge is an individual trait that makes us invariably gather into groups. It is the seed of culture. Setting up cultural networks in small groups, tribes and collectives makes each individual function a bit better than they would alone. Beyond this utilitarian vision, teaching is also a way of getting to know not only things and causes but other people as well as ourselves.
Teaching is an intentional behaviour through which a teacher bridges a gap in knowledge. This compact definition presupposes many requirements in cognitive machinery that enables us to teach and to learn. For example:
(1) Recognizing our knowledge of something (metacognition). Recognizing the knowledge someone else has of something (theory of mind).
(2) Understanding that there is a disparity between these two sets of knowledge.
(3) Having the motivation to bridge that gap.
(4) Having a communicational apparatus (language, gestures) in order to bridge it.
Now, I propose a radical hypothesis about the first two points that comprise teaching, which naturally derive from the idea of the teaching instinct.
My conjecture is that children begin to teach as if compelled to do so, without taking into consideration what the student really knows or even what they themselves know. They could, in fact, teach a doll, the sea or a stone. From this point of view, teaching precedes–and can provide the experience for–forging a theory of mind. Teaching helps to put oneself mentally in another’s shoes and to be able to attribute thoughts and intentions to others. In the same way, children teach things they aren’t fully knowledgeable of and, in doing so, consolidate their own knowledge. This is a way of revisiting and delving deeper into Seneca’s celebrated idea: Docendo discimus–through teaching, we learn. We not only learn about what we are teaching but we also learn to calibrate our own and others’ knowledge. In addition to becoming more versed in the subject, when we teach we also learn about ourselves and others.
We saw that learning is about expressing new information in the framework of the language of individual thinking. Teaching is an exercise in translation in which we learn not only because we review facts–hit the books, as we say–but because we carry out the exercise of simplifying, summing up, underlining and thinking about how the same problem is seen from another’s perspective. All these tasks, so intrinsic to pedagogy, are the essential fuel of learning.
Someone with a well-consolidated grasp of the theory of mind can reflect from another’s perspective and thus understand that two people can come to different conclusions. This can be demonstrated in the laboratory in the following way. The first person sees a packet of sweets. There is no way of seeing what is inside it. They also see how someone takes out all the sweets and puts screws in instead. Then Bill, who hasn’t seen any of this, comes in. The question for the first person is: what does Bill think is inside the packet? In order to respond, the first person must travel to the other’s thoughts.
Someone equipped with a theory of mind understands that, from that perspective, the most natural thing for Bill to think is that the packet is filled with sweets. Someone who does not have a well-established theory of mind supposes that Bill thinks there must be screws inside. This simple example serves for a wide range of problems that include understanding that the other person not only has a body of knowledge that is different from yours but also another affective perspective, with other sensibilities and ways of reasoning. The theory of mind is expressed rudimentarily in the first months of life and then is slowly consolidated during development.
Cecilia Calero and I corroborated the first part of the hypothesis of learning as a process of consolidating the theory of mind. We saw that children didn’t need to have calibrated a theory of others’ knowledge in order to teach. Children teach even when they barely have any idea of what the other person knows. What we still must discover, by carefully following the development of those little teachers, is whether the most interesting hypothesis is true: if, when teaching, the children forge and consolidate the theory of mind.
The second hypothesis of the teaching instinct–teaching helps to consolidate the knowledge of the one teaching–today has a far wider consensus. Seneca’s baton was picked up by Joseph Joubert, the inspector-general of universities under Napoleon, with his famous phrase: ‘To teach is to learn twice.’ And the contemporary version of this idea–according to which one way of learning is by sometimes putting yourself in the place of the teacher–begins with a concrete and practical necessity of our educational system. Assigning tutors to students is the most effective educational intervention. But assigning an expert tutor to each student is completely implausible. One solution that has been tested successfully in many innovative educational systems is peer tutoring, students who temporarily assume the role of teachers in order to complement their classmates’ education. This happens spontaneously in rural schools, where there are few students, of varying ages, who share the same classroom. It also happens, naturally, outside the school environment.
Andrea Moro, one of the greatest contemporary linguists, noticed that children’s mother tongue is not their mother’s language but that of their friends. Children who grow up in a foreign country speak their peers’ language more naturally than their parents’ tongue. Bringing peer tutoring to the classroom is simply installing in formal education something common and effective in the school of life.
Even if peer teaching is not as effective as expert tutoring, it has a great advantage above and beyond practical and economic considerations. The tutor also learns while teaching. This effect is observed even when the tutor and student are the same age and even if the teaching is reciprocal, meaning the children alternate their teaching and learning roles.
This is promising and should encourage the practice in educational settings. But there is an important caveat: the effect is highly variable. In some cases, the children improve greatly as they teach. In other cases, they don’t. If we understood when this practice is useful, we would have an effective recipe for improving education and, along the way, we would have revealed an important secret about learning.
That is what Rod Roscoe and Michelene Chi did discovering that tutors benefit more from their teaching when it fulfils these principles:
(1) The teachers rehearse and put their knowledge to the test, which allows them to detect errors, bridge gaps and generate new ideas.
(2) The teachers establish analogies or metaphors, relating the different concepts and assigning priorities to the information they have. Teaching is not listing facts but rather constructing a story that links them together in a plot.
These principles are very similar to a concept we have already looked at, the memory palace. The construction of memory is more similar to a creative process than to a passive storage of information in nooks and crannies of the brain. The memories become effective, strong and long lasting if they are reorganized into a reasonable visual plot, with a certain logic to the palace’s architectural structure. Now we can extend this idea to all thought. Students, when teaching, are organizing concepts that they’ve already acquired into a new architecture that is more propitious to remembering and, above all, to the construction of new knowledge. They are building their palaces of thought.