Albert Costa: The Bilingual Brain review – double-talking heads and what they tell us

Those of us who have to toil and sweat with other languages often feel a twinge of envy when we meet truly bilingual folk. That ability to switch codes, seemingly without any fuss, must confer so many benefits. More than ever, bilingualism blossoms across an increasingly connected world, often under the radar of social and educational policy. I know people who will claim to be no good at languages – in the formal, academic sense – and then phone their mum to chat in Urdu or in Greek.

It might even be the case that Britain’s varied bilingual communities – from Polish- to Punjabi-speakers – constitute a sort of hidden resource, invisible in the debates about the decline of languages in schools and scorned by the nativist politicians who now govern us. The same holds good for many other countries, far beyond those nations – from India and South Africa to Belgium and Wales – where language policy acts as a front-line (and divisive) issue. So a book that offers to explain what happens deep in the grey and white matter of the “bilingual brain” promises not just new insights into the neuropsychology of language. It may help us to understand how, and why, instant access to two languages (or more) blesses the people who speak with forked tongues.

In this (sadly posthumous) study, the Barcelona-based cognitive scientist Albert Costa lays his stress on neurology and psychology – rather than the social dimensions of language – as he scans the research to explain “how two languages coexist in the same brain”. Amiably written, and reader-friendly even when delving into the sub-cranial minutiae of bilingualism, his compact but data-dense book does throw out some intriguing ideas about the relationship of dual-language use to attitudes and behaviour. His references range from Douglas Adams's "Babel fish" super-translator to the emotional impact of reading Harry Potter novels in your first or second language.

Mostly, though, it’s the close-focus neuroscience of the “talking head” with a double wiring that concerns Costa. For a broader, less technical account of why speaking in two, or several, tongues matters so much, I’d recommend a complementary work: Marek Kohn’s Four Words for Friend from Yale University Press (full disclosure: he is one). If, in Costa, you sometimes miss the rich hinterland of culture beyond the wonders of the cerebrum, you’ll find that terrain generously mapped by Kohn. 

Costa undertakes a global trawl of significant research, and draws on his own career. He tells us how babies become bilingual (almost from birth, if they consistently hear and respond to two languages), and how adults code-switch to deploy the “orderly mixing” of languages without confusion that makes the rest of us so envious. He even demonstrates how, in old age, the lifelong command of two languages may delay the onset of dementia. Costa himself was a bilingual speaker of Spanish and Catalan, although with the former as his mother tongue. The vexed language politics of Catalonia evidently lent a special urgency to his investigations. 

All the more impressive, then, that he keeps up such a genial and companionable tone, free of rhetorical gestures or special pleading on behalf of one group or another. He does show how educational fashions have shifted, from treating the bilingual home as a potential brake on a child’s development (as happened in British schools until the 1980s at least), to grasping the learning advantages that the extra effort required from the “bilingual brain” can bring. However, he dismisses the crude fantasy of all-round bilingual superiority. Media features pretending that bilinguals are generally “smarter” than us (as even the New York Times proposed) get short shrift. Rather, many studies show just how hugely adaptable and resourceful the human brain is when challenged by tasks of many kinds. Its “orchestra” of capacities tunes up to interpret the world of sense data in various ways, all the way from the babies who learn to recognise and separate different language-sounds from their first weeks to the diagnosed Alzheimer’s sufferers, whose background in two tongues seems to postpone the ravages of the disease. Research in Toronto found a gap of several years between the emergence of dementia symptoms in monolingual and bilingual speakers. Scientists wondered if the effect might be due to other factors – the immigrant’s successful immersion in another culture, perhaps. However, a similar study in Hyderabad among people who had never travelled far produced the same results. “Bilingualism delayed the onset of symptoms of dementia by about four years,” Costa concludes.

Not all of Costa’s news is uniformly good for bilinguals or their prospective parents. The previous suspicion of the bilingual home in educational theory has some meagre grounding in the evidence. Children raised in such an environment pick up vocabulary slightly more slowly than their peers, with marginally slower verbal recall in their early years. The brain, though miraculously flexible, is simply working harder to process the double data-stream. Its “access to words is more costly”. On the plus side, the life-long cognitive benefits of mental movement between languages do sound formidable. Bilinguals, it transpires, have an enhanced ability to filter out interference.They may pay attention more efficiently. Also, they appear to be better at multitasking, and even bilingual infants show superior “cognitive flexibility”. Later in life, that extra storage – or “cognitive reserve” – may become available to offset not only dementia but other, milder deficits of the ageing brain. 

Perhaps Costa’s most striking illuminations come in not in the field of cortical activity but with the behavioural outcomes of the hard-working, language-switching brain. Bilinguals seem to possess more empathy with others; they develop a “theory of mind” (ie, the grasp of other people's mental states) earlier. They can more readily “change their perspective to that of their partner” in conversation. Bilingualism may also help reduce our “egocentric bias” in assessing events and situations. 

Costa’s final chapter, on decision-making, offers the most resonant discoveries of all. Here, I would want to take issue withthis book’s title. These sections by and large relate to anyone who uses a second language well rather than strictly-defined bilinguals, brought up with two near-equal tongues. Put baldly, people who work at a high level in a second language seem to operate more lucidly in it. It appears to neutralise cognitive and intuitive biases, to “reduce emotional intensity”, and to foster calmer and more rational approaches to problem-solving. For Costa, “facing problems in a foreign language leads to better decisions”. Which often means, of course, having greater empathy with your colleagues, partners or perhaps antagonists. Think of the multiple occasions in today’s world – from business negotiations to the Brexit talks – when native Anglophones sit down around a table with perfectly fluent (but not mother-tongue) English speakers. The Anglos may believe that, linguistically, they hold the higher cards. Costa’s revelations suggest that the opposite could be the case. The EU’s chief Brexit negotiator, Michel Barnier, would probably agree.  

Bilingualism proper may still to some extent depend on the accidents of birth and upbringing. Still, there’s much in Costa’s always-absorbing work to confirm the advantages that language-learning brings to anyone who opts to exercise those trainable blobs of grey and white matter at any stage of life. A pity, then, that this of all books should downgrade the contribution of its English translator from the Spanish. You might, if you hunt long enough, eventually find John W Schwieter’s name, but only buried in a tiny point-size on the copyright page. Shame on you – ¡Qué vergüenza! – Penguin. 

• The Bilingual Brain, and what it tells us about the science of language by Albert Costa (Allen Lane, £20)

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