Home The effects of multilingualism
Last update on October 10, 2019

Speaking only one language is common in many countries, but have we been looking at languages the wrong way all along? Multilingualism promotes mental health and opens doors to the world that otherwise might not have been available.


If someone tells you that coffee keeps you awake, or makes you sleepy, or has no effect whatsoever on its drinkers, and you didn’t know this, then you would thereafter know what coffee does. This piece of information tells you nothing about the effects of Cuba Libre, herbal tea, plain water, or any other drink. The statements are only about coffee.

Multilingualism is the future

If someone tells you that multilingualism is good for you, or causes language delay, and you didn’t know this, then you would also know that monolingualism could not be good for you, or that it doesn’t cause language delay. This is because human beings are traditionally seen to come in two complementary sets, those who use more than one language and those who use only one, so that what applies to the one does not apply to the other, and vice versa.

For historical (and bizarre) reasons, comparison has been the method of choice to gather information about multilinguals, an issue that I address in my book Multilinguals are …? . The core point is that comparisons are one-way: multilinguals are compared to monolinguals, but never the other way around.

There is no methodological reason for choosing one of the complementary sets as benchmark, or for not using comparison both ways around. And there is the good statistical reason that multilinguals outnumber monolinguals, which would make multilingualism a natural benchmark. Nevertheless, monolingualism took on this role with two consequences: that the benchmark is unquestionable, and that we are therefore entitled to ask questions of multilingualism that we don’t ask of monolingualism.

Making statements about multilingualism through comparisons with monolingual benchmarks further mislead us to believe that such statements indeed concern multilingualism, and multilingualism alone. But the assumption that takes multilinguals and monolinguals as complementary sets tells us that this cannot be so: statements about multilingualism, like statements about monolingualism, are statements about both multilingualism and monolingualism, as I’ve noted before.

Questions about monolingualism

This being so, I suggest probing monolingualism in the same way that multilingualism has been probed, through a set of popular FAQ:

  • What are the effects of monolingualism on language development?
  • Does monolingualism affect the development of a child’s single language?
  • Will children grow up confused with a single language in their environment?
  • How does exposure to a single language affect cognitive and social development?
  • Should parents speak their one language to their children?
  • What is the best method to raise children monolingually?
  • At what age should a child start learning a single language?
  • How do people become monolingual?
  • Should we expect delays in monolingual development?
  • Does monolingualism cause speech-language disorders?
  • If children are at risk of speech-language disorder, should they switch to several languages?
  • If a child is underachieving academically, should we recommend schooling in several languages?
  • What do we know about the monolingual brain?
  • What reasons are there to nurture monolingualism?
  • What are the advantages of monolingualism?
  • What are the disadvantages of monolingualism?

Context is everything

Questions like these have two things in common with their counterparts that go on being asked about multilingualism, both to do with ignoring contexts. First, they disregard the context in which the questions were originally asked, usually within the framework of experimental or fieldwork research. Second, they disregard the context in which the use of one or more languages is relevant. This is why, in my view, both sets of questions make as much sense.

The other problem with questions like the above is that you can’t answer them without, yet again, comparing multilinguals and monolinguals. Choosing description, instead of comparison, might be a good idea. We can then start asking questions about multilinguals, similar to the ones we ask about coffee. Like, for example, what do multilinguals do?