The Imitation Game

For our Space issue, Sam Bradley investigated how linguists are using artificial 'alien' languages to measure the ways that humans learn and develop the power of speech

From Star Wars to Avatar, writers of science fiction have often imagined the languages of extra-terrestrial beings. Usually, they’re defined by some quirk of alien biology, like Chewbacca’s ursine bellow or the ink logograms of Arrival.

Similarly, the origin of human language has been assumed to have been evolutionary – that is, an adaptation unique to homo sapiens, which emerged after thousands of years of natural selection. But language also changes in transmission from person to person, and at a far faster rate than the slow progression of natural selection – the way we speak English has changed beyond recognition since the time of the Saxons, but our biology hasn’t. The problem is that this ‘cultural evolution’ is invisible and hard to examine. So how can we investigate the mechanisms that drive it?

I spoke to Dr Kenny Smith from the Centre for Language Evolution at the University of Edinburgh, about language evolution. The reason cultural evolution is so important to understanding the development of language, according to Dr Smith, is because key features of language – grammar and meaning – seem to develop in humans whilst they’re learning to speak. He says, “Language learning is this kind of process that involves seeking patterns in the stuff you're hearing... and then when it comes to using a language to communicate, you want it to do certain jobs for you, like distinguishing between different kinds of things.

“Wherever you get those two pressures you get linguistic structure emerging. All the experiments we do are designed to understand how those two mechanisms work together.” Smith’s work at the university’s linguistics department involves teaching imaginary alien languages to human speakers – and seeing what kinds of structures and meanings they apply to them.

He says, “So the way it works is that you give a learner a miniature language and they have to learn it and then reproduce it. So you'd get a miniature language, expose it to a learner and see how well they learn it and that tells you something about how the learning process works.” The alien languages used in Smith’s experiments are really just lists of random shapes, matched with arbitrarily chosen labels. Any meaning to the labels, or rules applied to their usage, is invented by the speakers. According to Smith, the transmission of the alien languages between speakers is a little like Chinese Whispers; with each new speaker, the language gains rules and structures, and begins to behave like a real language.

The experiments are not so different to an example from the real world – that of Nicaraguan sign language. In the 1980’s, pupils at the country’s only deaf school managed to spontaneously develop their own, unique form of sign language. The language they created offers clues about the underlying structure of language – and how much of it is contained within our genes, and how much grows out of its usage.

New computer modelling techniques would appear to suggest that both processes act simultaneously, and “shape each other in interesting ways.” For instance, Smith says, “you still get these underlying adjustments in the genes - the evolution of slight biases for particular kinds of structure - so there you have biology contributing to the cultural evolution side. In reverse, because you have the language changing really fast [relative to natural selection] as a result of cultural transmission, that actually speeds up the biological evolution stuff... so you get the right genes evolving faster than you would otherwise expect.”

Smith hopes that developments in the field will allow linguists to reconcile the conflict over how language develops – as a product of natural selection or of cultural evolution. He says, “Once people figure out a bit more how genes build brains... then we'll be able to start picking apart how these co-evolutionary relationships play out in the real world.”