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.
This is a rigorous book about complex science, and much of it could have been intractably technical or riddled with statistics. But Costa has a winningly informal style, a deadpan wit, and mixes laboratory findings of cognitive neuropsychology with examples from everyday life, TV programmes, sports and politics. In one set of cognitive tests, he shows how people are more risk-averse in their second language, and more gung-ho in their first. Costa suggests the practical applicablity of such research by advising us to visit casinos where people speak a language we are less comfortable in – it substantially reduces the likelihood of our going home shirtless and barefoot.
Albert Costa (a Catalan-Spanish bilingual) died last year, and this book is a great testimony to his lifetime of research into the subject. Although peppered with a few technical aspects of neuroscience, it’s very readable: the prose is gentle, anecdotal, witty, personal and – despite the many controversies – balanced. He doesn’t deride monoglots (they have advantages too), but simply invites us to wonder what happens if you double up on what is already an extraordinary human ability – language... It’s a charming book. Summarising decades of academic research without being dull, Costa is generous to his peers and gracious where he demurs from their findings. He hedges a lot of bets, as one must in measuring anything inside the human head. But he leaves you in little doubt that the brain of bilinguals is, in tiny but important ways, provably different.
The Bilingual Brain will hopefully be a popular rejoinder to these persistent misconceptions. As Costa informs us, no evidence of a “cognitive bilingual disadvantage” exists. But neither does Costa swing too far the other way now the debate has shifted to a hypothetical advantage. The neurological evidence, in Costa’s telling, shows bilingualism has no “dramatic effects on linguistic capacity or any other cognitive domain”.
What this book makes clear, though, is the extent to which the human brain is still unexplored territory. Being focused on the way the brain works, it perhaps unavoidably overlooks what may be the best reason for learning new languages: it is fun, and sometimes it can even help you to see the world in a new way.