For the past few weeks, I have been discussing the design features of language, and how we can use them to compare our communication systems to those of animals. So far, we have discussed features that are present in both human and animal communication. Today, we will start talking about a final feature that is present in humans and animals before discussing some features that are only present in human communication or have very limited examples in animal communication.

The first feature to discuss today is the idea of tradition and cultural transmission. This feature states that communication is passed down from the elder generations of a species. This is not widely spread in animal communication, but it does exist in primates and birds. The alarm calls that we have discussed previously in primates like capuchin monkeys are often specific to a specific troop and not the species as a whole. This means that the way the calls were formed needed to be passed down from the elders of the troop to the younger generation. These predator calls fit the definition of cultural transmission because we do not have any evidence of a primate raised in isolation developing it’s own system of calls.

In birds, the songs that they produce have a cultural transmission aspect to them. Each individual bird does have its own unique voice, but the songs that are produced by birds raised in isolation will often be vastly different from other birds of the same species. This means that similar to our language, it needs to be passed down from generation to generation in these birds. This does not quite completely fit the definition of this design feature though because even birds raised in isolation will still develop some sort of birdsong for mating purposes. In humans, it is impossible to learn language without interacting with other humans and having it passed down in some way.

We know that cultural transmission is necessary in humans because if you remove an infant from interactions with all humans, that infant will have an extremely difficult time learning language at a later date. Ethically, we are not able to prove this in an experimental setting, but we do have some evidence that this is true in some extreme cases. The most famous example of this that is widely discussed in psychology and linguistics literature is the case of Genie.

Genie is the pseudonym of a child discovered in 1970 at the age of 13 who suffered from extreme neglect and abuse. At the time of her discovery, Genie had little to no language skills, which made Genie a highly sought-after case study by linguists and psychologists at the time. After time and training, Genie was able to learn limited language and social skills, but was never able to fully acquire a first language in the same way that most children do.

Cases like Genie, while tragic and extremely horrible, have done a lot to inform language acquisition research. The case of Genie provides evidence of the importance of transferring language from one generation to the next because without it, humans are incapable of acquiring a first language when left to their own devices. Compare this to cases of animals that are raised in isolation away from other members of their species who are able to fully develop a complete vocal range that is indistinguishable from a member of that species raised around others.

The next feature we will talk about today is learnability. Learnability means that the learner of a communication variant can learn to communicate using other variants. In the case of us humans, this consists of our ability to learn another language. As a speaker of English, I am able to learn a language like German or Mandarin with little difficulty and eventually I would be able communicate to native speakers of those language with no problem.

This does not mean it is easy to learn another language, but it is possible for humans. Compare this to the animal kingdom where we have no evidence of an animal learning to communicate with another species using a communication system that is not their own. You could try to make an argument for gorillas learning sign language in certain cases, but as we will see in some of these other features, they are not truly learning the system. The most famous example of this is Koko the gorilla who knew more than 1000 unique signs and was able to combine them in novel ways to communicate. The biggest thing that prevents us from saying that Koko fully learned the system is the fact that there was an upper limit to her knowledge.

Although Koko knew over 1000 signs, that is only a tenth of the estimated total amount of signs in American Sign Language. In addition to this, there is also the ability to finger spell words which do not have their own unique sign yet, meaning that there is an infinite number of ways that ASL users are able to communicate ideas. This is not to diminish the impressive knowledge that Koko had, but it is inaccurate to claim that she was a full and fluent user of sign language as we know it.

Another design feature that sets us apart from animals is known as recursion. Recursion is the ability to use a communication system to make infinitely large utterances through a process known as self embedding. This is the feature that allows us to craft infinitely long sentences and ideas by embedding clauses within clauses within clauses.

Human ideas are not limited by anything other than our own mortality and lung capacity. The best way to see this is add onto a sentence to make it infinitely long. Take the worlds longest sentence recognized by the Guinness Book of World Records, a sentence that is 1287 words long in William Faulkner’s novel ‘Absalom, Absalom!’ This sentence is excessive, but we can make it a bit longer by simply saying something like “Faulkner wrote” and then quoting the entire sentence. And now you could imagine infinite iterations of adding on a word here and there to extend this sentence out until the end of time.

The final feature we will discuss today is reflexiveness. Reflexiveness is the ability that we have as humans to use our communication to talk about our communication system. This one is a little bit heady and meta, but it is the core design feature that allows a field like linguistics to exist!

The fact that we are able to use the English language to make observations about the English language and then communicate those observations to another person using the English language is quite amazing once you take a step back and look at it from the outside. No animals are able to use their own communication system to talk about their communication system (or at least we don’t have evidence of it). It is unlikely that we are simply missing something in animals because it does require a sophisticated level of intelligence.

So it is plain to see that these features definitely set us apart from other animals. There are still four more to talk about though, so come back next week when we finally conclude this series on the design features of language!

Thank you for reading folks! I hope this was informative and interesting to you. Be sure to come back next week when we start to talk about the uniquely human design features. If you have any topics that you want to know more about, please reach out and I will do my best to write about them. In the meantime, remember to speak up and give linguists more data.