October 25, 2021

I, Science

The science magazine of Imperial College

Being bilingual can help you on holiday, but does the evidence agree that it makes you smarter too? Ian Sillett investigates.
The part of Canada where English and French are both frequently spoken is called ‘The Bilingual Belt’

Some are born multi-lingual, some become multi-lingual, and some remain resolutely and stubbornly monolingual. The latter obviously struggle on foreign holidays, but it turns out that they may also be intellectually and even medically worse off as a result.

The most comprehensive estimate for the number of different languages in the world is the Ethnologue which shows a surprisingly high 7102 living languages across all countries. The sheer diversity of human language is incredible, yet the same basic aspects are shared throughout the world.

Language is the way we communicate with each other, and is used to convey messages to a listener. Of course, not all language is spoken. We can use formal sign language when communicating with those of varying degrees of hearing loss and we all exhibit unconscious body language to enhance our spoken messages. But this article concentrates on the spoken word.

When speaking, we use our mouths and throats to create a series of sounds that represent words. These words in turn mean different things and in that way the pops, clicks, and hums of our language are almost like a code between two speakers. We can decode these sounds into language so fast we don’t even know we are doing it.

When children learn language, they must first learn to distinguish words from the constant stream of noises we make. Adults don’t tend to pause between words as a rule, so infants learn to use statistics to pick out common sound combinations. These are cultural and vary across the world and in fact, some children never learn certain sounds not used in their native language – for example, the Spanish rolling ‘r’ that English lacks.

Native Japanese speakers do not differentiate between ‘r’ and ‘l’, instead using a single sound. Researchers at the University of Indiana showed in 1994 that Japanese adults could be taught to perceive the difference relatively quickly. So becoming multi-lingual can have a direct effect on the
wiring of their brain, creating new connections to comprehend new sound combinations.

Children brought up in multilingual environments therefore need to learn more sounds and recognise two or more separate statistical models of noises that represent the words they need to learn. It is hardly surprising therefore that research at the Hungarian Academy of Sciences has shown that infants brought up in bilingual environments demonstrate increased problem solving ability, even before they have learned to speak. Much of our language learning is complete before we utter our first words.

Further work by Kara Morgan-Short at the University of Illinois has indicated that some adults are able to pick up language through immersion, in the same way as infants, but only if they are adept at pattern recognition. It is therefore never too late to start, which is good news for the many millions of us who try to learn new languages at school or university.

In fact, there is a wide variety of research which suggests that bilingual people have better cognitive function, whenever they learned. When a person’s vocabulary extends to two languages, the number of words with which to describe an object is doubled. Yet only half of those are suitable for the current situation or group of friends. That makes the brain work twice as hard to solve the problem of which words to use and when. Remarkably, the brain can achieve this without problems, but must operate with higher cognitive effort.

This increased cognitive effort causes bilingual people to be better at other real world skills such as reasoning. They have more cunning as problem solvers and more efficiency as planners. They are so used to switching between languages that moving on from one problem to another is effortless. They are better at spatial memory tasks, changing priorities and they have better concentration.

It also appears that bilingualism has medical benefits for old age too. Work by Fergus Craik at the Rotman Research Institute in Canada suggests that the increased cognitive load delays the onset of dementia by about five years, and other research shows it can also reduce the effects if and when we do begin to suffer.

A bilingual sign in Montreal

All of this is pretty incredible, but there must be a downside. After all, if you ask a computer to do two tasks at once it does so, only slower. If you ask a human to do two tasks, they will do one at a time, or do both simultaneously but dreadfully. So what’s the cost?

There are a couple of well-documented disadvantages of multilingualism. People who speak two languages never attain the fluency as someone who speaks only one. The brain only has room for so much vocabulary and inevitably, obscure nouns and lesser-spotted adjectives can wander from a bilingual mind.

People who speak two languages also struggle to recall certain words, twice as often as those of us who only speak one. It is as though their brains, overburdened with working out which words are appropriate, have nothing left with which to select any words at all.

Nevertheless, how often do we need to say “the expeditious, russet mammal with a reputation for cunning, vaults keenly over the somnolent canine?” instead of “the quick brown fox jumps over the lazy dog?” How much of a disadvantage is it if one needs to say “urm, how do you say…” a few more times than is usual? The suggested advantages to bilingualism easily outweigh the disadvantages. But just how true is this in everyday life?

Don’t take this the wrong way, there are many reasons to learn a new language. You will get fewer surprises in foreign restaurants, better job prospects and you will satisfy your cultural and intellectual curiosity. There are even proven benefits for the health of our brains in old age, and the good news is that evidence shows it doesn’t matter how late you start. What you shouldn’t do is assume it will make you smarter.

Ian Sillett is studying for an MSc in Science Communication

Images: Bilingualism in Canada; Bilingual sign (Wikimedia Commons)