One of Chomsky’s more controversial claims regarding language is that it is not a communication system, rather that it evolved as a system of thought which was then externalized and used for communication. It’s perfectly understandable why this would be controversial, as it seems false on its face. We use language all the time to communicate. In fact it may seem like that’s all we use it for. If we think about it briefly we can come up with many non-communicative uses of language. We talk to ourselves to help ourselves think, we use it for play, we use it to aid our memory, and so on. It’s uncontroversial both that language is used communicatively and non-communicatively, but the question is: Which came first?

While there are arguments on either side of the debate, there isn’t a tonne of evidence that speaks directly to it. We don’t have time travel to go back and observe the early development of humanity, and our tools for objectively testing either claim on present-day humans are still too blunt to be of any use. What we can do is compare language to an unambiguously communication-first system: physical gestures. We certainly use gestures to augment language, but we certainly can use language without gestures and gestures without language. When we gesture without language we are certainly communicating but we aren’t using a language.

So, If you’re on board with me so far (language and gesture are distinct systems, and gesture is communicative), we can get some evidence that language is not inherently communicative. If it were communicative, we would expect it to operate like a communicative system (i.e., gesture) in a context where communication is not called for.

The test is as follows: First, be alone (the next time you find yourself alone in a room would be a good time to try it out). Second, don’t be reading, watching TV/Movies, or listening to anything (Isolate yourself from virtual people). Once you’re isolated, say something aloud. It doesn’t matter what, whatever comes naturally. Next, gesture. Point at something, shush the room, make an obscene gesture. But make sure it’s not accompanied with any language. Consider how unnatural one of these tasks felt compared to the other. If you’re like me, one will feel a bit odd, and the other will feel like one of the strangest things you’ve ever done.

In The Language Myth Vyvyan Evans presents the proposal that human language is a species of communication technology like writing systems, telephones, or computer networks. Just as we have no innate capacity for reading/writing, dialling phones, or clicking on links, we have no innate capacity for language. Instead, we humans were endowed with increased general cognitive ability, which allowed us to iteratively develop language, writing, telephony and computer networks. We know from archaeology, historical records and our own memories that communication technologies such as writing systems, telephony, and networked computing (along with a host of non-communication technologies) have undergone periods of exponential improvement. Science, philosophy, and math has shown in some cases that certain technologies (e.g., computer programming languages) have advanced to their logical or physical limits, or in other cases (e.g.,Audio encoding) have advanced to the limits of human cognition. 

This proposal makes a prediction about language. Either it is still advancing,  it has reached its logical limits, or it is at the limits of human cognition. The second option has been shown to be false as there are classes of language which are more expressive than human language. The first and third, however, are viable hypotheses. The first hypothesis, that language continues to improve like, say, photovoltaic cells, seems like it would be quite demonstrable if it were true. Since we have known for centuries that the language spoken by a given generation varies, albeit slightly, from that of the previous generation, a scientist seeking to provide evidence for the first hypothesis would only have to demonstrate a general trend of improvement in a language across generations. I know of no studies that provide such a demonstration. This leaves the third hypothesis: that language has developed to the limit of human cognition. Notice that the third hypothesis is the UG hypothesis: that humans are born with an innate capacity for language. Absent any evidence of language improvement, Evans’ proposal is the UG hypothesis.