The Secret Life of the Mind

by Mariano Sigman

  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.*

  Spikes of culture

  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.

  Docendo discimus

  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 l
ife.

  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.