A proposal in Germany to make all migrants speak German in public and at home has ignited a heated debate about immigration and language.

The proposals come from the German Christlich-Soziale Union (CSU), the more right-wing Bavarian sister party to German chancellor, Angela Merkel’s Christian Democratic Union (CDU). The party – which is part of German’s ruling coalition and has three cabinet ministers – will vote on the issue at its party conference on December 13 and 14, making the possible introduction of legislation on the issue one step closer.

Both in Germany and across Europe, immigration and integration are the buzzwords of the day. There are regular debates about those citizens who feel “alienated” in their own country by large numbers of immigrants speaking another language.

If immigrants intend to stay in a country for any length of time, there is no doubt that it is helpful and reasonable for them to learn the language as quickly and fully as possible. But linguistic research shows that it would not be helpful for migrants to stop speaking their native language on the streets and at home – and it could actually be harmful for their children’s language learning.

Demands by politicians for migrants to abandon their first language have cropped up before in the UK – and not only from the political right. When he was still home secretary, Labour’s David Blunkett demanded that Asian families should use English in the home – being brought up bilingual, he feared, would lead to some kind of inter-generational “schizophrenia”.

But not even the UK Independence Party’s Nigel Farage has gone as far as either the German CSU or Blunkett on the issue. To Farage, migrants who speak their native languages on trains and in other public spaces make him feel “awkward” and “uncomfortable” – but he has remained quiet on what they do in their homes. This leniency may be linked to the fact that Farage, whose wife is German, has first-hand experience with raising bilingual children. Perhaps he knows that, far from leading to “schizophrenia” and poor English skills, it is probably one of the best things that parents can do for their children, if they have the opportunity.

Nurture in your native language

Migrants who avoid speaking their native language at home may actively harm their children’s development. There are two main reasons for this. First, the different languages which we acquire throughout our lives have different emotional significance. For example, multilingual people tend to feel that phrases such as “I love you” carry the most emotional weight in their native language.

We also tend to approach situations in the language in which we experienced them ourselves – and this translates to a very deep-seated instinct for most bilingual people to talk to children in the language in which they experienced nurture and care.

In my own work with German-Jewish Holocaust refugees, I heard people tell me that their native German repulsed them and they never normally used it, due to the persecution they had suffered at the hand of the Nazis. But many also said that it seemed natural to talk and sing to their own babies and grandchildren in German. Putting pressure on migrants to abandon their native language in these kinds of contexts can be detrimental to the close emotional connection that every parent should feel with their child.

Hearing mistakes doesn’t help

All language learners, whether children or adults, have the ability to recognise statistical patterns. Language learning is based on the frequency with which certain structures occur in the speech a learner hears. If children are permanently exposed to non-native structures from their parents, far from being conducive to their acquisition of the main language of the country where they’re growing up, it may lead to confusion and delayed language acquisition.

If not, you better learn quick.German board via natalia bulatova/Shutterstock

This is suggested by studies on English and Turkish children growing up in the Netherlands, who appear to have persistent problems in using the Dutch article system correctly – possibly due to the fact that their parents never mastered it.

So it appears that the frequency with which migrant families use their own native language correlates strongly with the children’s proficiency in that language – but not at all with the language of the country they’re living in.

Enforcing academic disadvantage

In this context it is somewhat ironic that the recent demand that German should be spoken in the home was made by the CSU – the same party which, two years ago, insisted that parents who do not make use of any state-supported childcare should be paid EUR 150 per month. Recent studies show that this initiative has been particularly popular among migrant families.

The fact that these children will not be sufficiently exposed to native German from their peers and adults at a childcare centre will undoubtedly lead to lower levels of proficiency when they reach school age. The demand that these families should be forced to use German in the home will aggravate, rather than remedy, this situation.

It is the level of proficiency in a child’s native language, not in the one in which they grow up – their “environmental” language – which is the strongest predictor of later academic success.

Recent research has also shown that bilingual people have better mental flexibility and can adapt to new tasks better and faster than monolingual people. This so-called “bilingual advantage” becomes particularly important later in life: bilinguals are slower to show the typical signs of cognitive ageing – and bilingualism can even delay the onset of age-related cognitive disorders such as dementia or Alzheimer’s by up to five years.

So it may actually be harmful for children if their parents don’t speak to them in their native language. And the migrants themselves would not benefit either. This is not how language acquisition works. Of course it is good to surround yourself with naturalistic language input, but if the language a learner is exposed to is unsystematic (since the other speakers are also novices, who produce a large number of errors), this will only lead to confusion, as this famous clip from the film Casablanca shows.

Charming, but not the way to learn.

Monika Schmid receives funding from the Dutch national funding body NWO and the Economic and Social Research Counil.