How can two languages co-exist in the same brain? Tim Smith-Laing on the superpower of bilingualism
In the central London primary school where I teach one day a week, around two thirds of the children live their lives in two or more languages. When I asked a class of eight-year-olds to help me put the numbers 1 to 10 up on the board in the languages they knew, we ran out of time before we could get through them all. By the end of the hour, the board had Polish, Italian, Arabic, Kurdish, Bengali, Pashto and Hindi on it. Had we had more time, we could have added Korean and Spanish, too. I do not mind admitting that, at times, it seems slightly redundant to be teaching the same children Latin as a basis for expanding their English grammar and literacy.
If two thirds of a class seems like a lot, it probably should not. While there is little pressure on Britons and Americans to learn foreign languages, Albert Costa points out in The Bilingual Brain that “the majority of the world’s population can communicate in more than one language”. Though a certain amount depends on how you choose to define bilingualism, it is, in global terms, “the rule rather than the exception”. So while my class might seem out of the ordinary in Britain – where only 38 per cent of us speak a language in addition to English – they are entirely representative of the wider world. Just like them, two thirds of children across the world are raised in bilingual environments.
Those of us who were born into the other, monoglot third, and who have struggled to learn foreign languages to any degree of competence later in life, may well be jealous. It is, of course, possible to learn a language almost as well as a native speaker – Joseph Conrad, for instance, took up English in his 20s, and went on to become one of the greatest prose stylists ever to have written in it. But it is also an enormous challenge: learning, understanding and replicating the grammar, phonological properties and everyday pragmatics of languages to fluency as an adult is no mean feat. Even Conrad, rather comfortingly, never lost what was by all accounts a nearly impenetrable Polish accent. For my own part, I have recently been trying to brush up the Japanese I spent three months learning and 12 years forgetting. After several months of daily sessions, my app informs me that I now know nearly all the ideograms that would be familiar to a Japanese six-year-old. Nearly. To be born into a language is to be a fish in water; to learn one is like wading through treacle.
Not for nothing, then, is bilingualism sometimes talked about as something akin to a superpower. Whether it actually is, though, is another question. Indeed, as The Bilingual Brain makes clear, it is a whole slew of questions. In the first place, given that it is the norm in much of the world’s population, “Is there anything special about being bilingual?” If there is, and given the vast amount of information implicated in “knowing” a language, how do two languages coexist in the same brain? Does such coexistence confer, beyond communicative flexibility, tangible cognitive benefits, or might it, in fact, do the opposite, and bring cognitive disadvantages? In either case, how exactly might it affect decision-making, the attentional system or even the development of neurodegenerative diseases?
The slight issue with The Bilingual Brain is that there are, in fact, rather more questions than there are answers. Before his premature death in 2018, Costa was a leading researcher in the field of psycholinguistics, and this book approaches its subject with a scientific caution and care that is by turns admirable and frustrating. The five chapters are dedicated successively to the early formation of bilingual babies’ brains; the representation of languages in adult brains; the effects of bilingualism on language processing in general; the attentional system; and our decision-making processes. These chapters act, more than anything else, as a primer in the ingenious techniques by which experimenters have tackled the questions around bilingualism.
But despite the ingenuity, the actual results, as Costa notes, show only slim differences in cognitive outcomes between bilingual and monolingual brains – and some of these have, themselves, proven hard to replicate reliably. So, while bilingual children seem to develop “theory of mind” (our empathetic sense of the otherness of other people) earlier than monolinguals, and while making decisions in a non-dominant language seems to encourage slower, and therefore more rational, choices, proof of other “behavioural advantages” is thin on the ground. There is, as Costa readily admits, a lot to be found out.
What The Bilingual Brain never really broaches, though, are the very obvious joys of knowing, and learning, languages. For those of us who enjoy wading through treacle, the knowledge that bilingualism is probably not a superpower or anything like it should be rather heartening. I, for one, am really looking forward to being able to read Japanese almost as well as a seven-year-old.
The Bilingual Brain is published by Allen Lane, £20.00. To order your copy for £9.99, call 0844 871 1514 or visit the Telegraph Bookshop