A few years ago, the Smithsonian’s National Museum of the American Indian organized an exhibition in California, in homage to the so-called code talkers. The expression code talkers refers to a small group of mainly Navajo Native Americans who worked for the US Army during the Second World War to codify its messages. In 1943, when the US was fighting the Japanese, the American high command came to the conclusion that a number of failed maneuvers by their troops were the result of Japanese forces having anticipated their movements, and that the only explanation of this was that Japan was deciphering their secret messages. The US therefore decided to stop using its normal encryption code, and instead used Navajo, a natural language. Orders written in English were translated into Navajo for radio communication, and this resisted all attempts by Japanese cryptographers to decipher them.
Mark Baker has interpreted this episode as an interesting paradox: whereas languages are clearly very different, they are all part of one unique system which is a common and specific faculty of our species. So, the paradox is that the Navajo language seems to be extremely different from English (and Japanese), with experienced Japanese code-breakers incapable of deciphering it (unlike artificial codes, which they did de-code); however, Navajo must also be very similar to English, otherwise Navajo interpreters could not have accurately translated the original English orders into Navajo, and then back again into English.
Indeed, there are clear reasons for thinking that human languages are very different. The most obvious illustration of this is that speaking one language (for example, English) does not normally allow you to speak and understand others (for example, Spanish or Russian). Yet we also know that language is a property common to all humans: everything that is said in one language can be translated into any other language, and any newborn child can learn any language in the world without effort.
How can we explain this apparent paradox? The first thing we need to understand is why different languages exist at all. Why isn’t there a single language for all human beings? The answer suggested by Noam Chomsky is rather surprising. He argued that if a Martian scientist came to Earth and examined our species, she would conclude that all human beings speak the same language. What Chomsky meant was that we need to take a step back from our own languages, which are so familiar to us, and instead adopt a more general point of view, just as we do when we analyze the communication systems of other species. When we observe the natural world, we see that each species (blue whales, chimpanzees, woodpeckers or honey bees) has a unique communication system. Each species is equipped with a communication system of its own, and it is biologically determined. Thus, members of that species do not have to learn it; rather, it is part of their nature, in the same way as fins, hair, beaks or the instinct to look for pollen are. For that reason, the communication system is the same for all members of a species. If you are a blue whale, you will “speak” like a blue whale, not like a bee.
‘Why should our species be different?’ Chomsky asked. He and others claim that our own species is not different. Such linguists focus on the unity of human language, regardless of the differences between particular languages. But, of course, this cannot be the whole story. There are about 6,500 different human languages in the world, that is, about 6,500 different ways of speaking that do not allow mutual understanding between their speakers. Where do all these languages come from, if all humans have the same natural instinct for language? To answer this question, we have to look more closely at the ‘language’ of other animals, such as birds.
Ethologists have observed that there are subtle differences in the songs of different groups of birds from the same species. Birds are not limited to simply imitating the songs of adults; instead, they produce certain innovations that make the songs that they sing slightly different from the ones they have heard. This leads successive generations of birds to hear songs slightly differently from those of the previous generation, and as a consequence of this, birds of the same species from different regions sing slightly different songs.
This situation is similar to what happens with human languages. We’ve all noticed how two people from different cities in the same country often speak differently, using different words or sounds, for example. (These variations are what linguists call dialects, that is, different ways of speaking the same language). It is important to note that the difference between dialects and languages is not a class difference, but a matter of degree of similarity between different ways of speaking. So, we consider a person from Boston and another from Texas to speak two different dialects of the same language (English), because these forms are very similar to each other (usually their users understand each other). On the other hand, we consider that speakers of English and French are not speaking dialects of the same language but different languages, because these two ways of speaking are far less similar (and normally their users do not understand each other). It could be said that birds only have ‘dialects’ (and not ‘languages’) because the margin of variation in animal language is very small, while users of human language not only have dialects, but also different languages (that is, dialects that are not mutually intelligible) because the range of variation allowed by biology in human language is far greater than in animal language.
The question, then, is why human language allows much more variation than the communication systems of other animals. The answer has to do with the kind of animals we are as humans. Of course, we are animals (not spirits or angels), and as such we have a language which is specific to our species, common to all people, and very different from that of any other species. However, we are special animals, in the sense that we are much more capable than others to learn from our environment and to develop and transmit culture. Human beings have a period of growth and learning which is longer than other animals. When we are born we are immature (according to biologists, this is probably because of the large size of babies’ heads) yet nature has endowed us with an incredible capacity to learn. In addition, our language is a great deal more complex than that of other species, and therefore we have to spend the first few years of our lives interacting with other speakers so that our capacity to speak language develops fully.
We have already seen that in the rest of the animal kingdom the ‘language’ of each species is fully biologically determined. In these cases there are no dialects (nor, of course, languages). Some species, such as whales or certain birds, do have a capacity to learn parts of their language system from the environment, and this causes ‘dialects’ to emerge in individuals living in different areas. The case of human animals is a much more complex version of this. Nature has designed us so that we can learn many aspects of our complex language from the environment. As a consequence of this, it is normal for different dialects to emerge, and also that these dialects will differ from each other over time, a process which is intensified because of the geographical distance between human groups. All this gives rise to different languages. In fact, not many years ago, languages as different as English, German, Norwegian or Icelandic were dialects of a single language, which linguists call Proto-Germanic.
However, this diversity does not mean that the various human languages do not share an essential set of design features specific to humans. To get an idea of how this can be, let’s think about the different varieties or breeds of dogs. As can be seen in the picture below, the different animals are very different in color, size, shape of the head and ears, etc., but they are all dogs, and there are no individual dogs that are somehow more or less dog-like than others. Although they seem very different in terms of their surface features, they all share common internal properties that define them as a natural class (versus cats, for example).
Or consider next picture. All these are children of the same species, although it is true that they have different superficial features (such as hair color, skin tone or eye color). An important question here is: how many different smiles are there in the photo? Just one. A human smile.
Languages seem very different, but since they are variations of the same language faculty, we can say that they all serve the same functions, have the same degree of development, and deserve the same respect.
This text is based on a draft written for a journal popularizing science to kids.