“You can never understand one language until you understand at least two” – bilingualism from a scientific point of view

Over the last 20 years, we have learnt a lot about bilingualism and its impact on the human brain. Never before was so much research conducted with such unambiguous results. Tests in bilingual or multilingual people are carried out currently not only by linguists but also by anthropologists, neurologists, psychologists and behaviourists.

Results of all research on bilingualism are quite similar, although they usually refer to different areas of life or brain activity. As Professor Gigi Luk of Harvard Graduate of School Education says, bilingualism is something that shapes us for the rest of our lives, which is the reason why so many schools decide nowadays to run bilingual classes from the earliest years of education.

Yet, before we pass on to enumerating advantages of being bilingual, we have to specify what we are actually talking about. The terms “multilingualism” or “bilingualism” are unfortunately not unequivocal. Different researchers define them in their studies in different ways. Moreover, there are several types of multilingualism. We assume in this article that to be bilingual you have to be exposed to two or more languages since you are born or you have to learn them later.

Divided attention

The ability to speak two languages comes down actually to being capable of not speaking one of them at a given moment. This is related to a more developed inhibition process, i.e. the ability to refrain from doing something in the procedural memory system. This process is better developed in multilingual people, which also enhances attention divisibility.

Researchers claim that this feature is present in people who have been bilingual since they were born. We still do not know, however, whether learning another language at an older age has the same impact.

Brain work

Attention divisibility is just one of numerous cognitive abilities which are developed to a greater extent in multilingual people. These abilities include also perception, memory and cognitive control. Thanks to multilingualism, we are able to better control executive processes performed by the brain, which are generally responsible for activities such as multilevel thinking, staying focused and multitasking. Multilingual people are less likely to get distracted and are able to focus on several activities at a time (or devote more attention to some activity than to another one).

Moreover, maintaining high brain activity through switching between languages or just learning them can delay aging symptoms characteristic for this organ. These include such serious diseases as dementia and other cognitive disorders. Research shows that Alzheimer’s disease progresses more slowly and has less impact on multilingual patients than on those speaking only one language. What is more, the symptoms of senile dementia in multilingual people occur up to five years later compared to monolinguals. This applies to people who learn foreign languages at any stage of their lives. Learning languages has similar effects on the brain as physical exercises on the human body, making it simply healthier and able to regenerate faster.


Children raised in a multilingual environment have to learn quickly which language they should use is a given situation or talking to a given person. Research shows that such children outstrip their peers – already at the age of 3 – in prospective thinking and drawing conclusions about other people’s state of mind. These elements are of key importance to emotional development of people, which translates into greater empathy in multilingual children.

Tolerance, diversity, adaptability

The theory suggesting that language changes personality was explored already in 1968 by Susan Ervin, a sociolinguist, who herself spoke two languages. Susan Ervin noticed then major changes in terminology used by research subjects (who were requested to complete a few sentences in two languages) and the intention and purport of completed sentences. Ervin claimed that this was due to cultural differences which are language-inherent. More recent studies (e.g. those carried out in 2003 by Jean-Marc Dewaele and Aneta Pavlenko) confirmed this theory.

Such personality changes are in turn correlated with greater tolerance and more developed adaptability to changes.

Are there any disadvantages?

Still at the beginning of the 20th century, it was suspected that multilingualism could have adverse effects on speech development or even the IQ level, yet these theories have been disproved.

Some studies have shown, however, that multilingual people’s vocabulary is less extensive and that their verbal abilities are slightly less developed. Compared to monolinguals, they are more often in situations in which they cannot find the right word to describe a given situation or problem.

Summing up, even if you have not been born into a multilingual family, it is worth learning foreign languages. This is first and foremost a great exercise for your brain, which slows down its aging, and good fun – by learning a new language you also get to know the culture of a given region, its history, cuisine and customs. As Rita Mae Brown said “Language is the road map of a culture. It tells you where its people come from and where they are going”.

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