The recent article in The Scotsman, in which the Conservative education spokesperson Liz Smith described Gaelic-medium education as a “deeply troubling step” has already generated, as could be expected, a lively and passionate discussion. Much of the ensuing debate has been based on political, ideological and indeed, emotional arguments. So maybe it’s time to bring in some scientific evidence.

Liz Smith’s critique of Gaelic medium education contradicts a huge and growing body of evidence suggesting exactly the opposite of what she was claiming: knowledge of different languages, education in different languages, learning and using different languages have all been shown to have beneficial effects on cognition. There is a wealth of evidence suggesting that bilingual children outperform monolingual ones on cognitive tests; interestingly, some of these studies have been done specifically in Gaelic-medium education.

However, these effects are not confined to childhood, they continue across the lifespan leading to a slower cognitive ageing, delayed onset of dementia and better cognitive recovery after stroke. Remarkably, an improvement in attention has been documented in participants of all ages already after a one-week intensive language course. And the language used in this study was… Gaelic!

The idea that learning a new language harms the knowledge of existing ones is based on a “limited resources model”. Its main assumption is that, as there is only a limited space in our mind and brain, all inputs have to compete with each other, and adding something new means invariably taking something else away. Translated into the world of language, everything done in any language other than English weakens English and hence, harms children’s education. (The fallacy of the limited resources model when applied to multilingualism is explained in a Bilingualism Matters blog post.)

This intuitively convincing model has a crucial shortcoming: it assumes that all pieces of knowledge that we learn are unconnected. This is clearly not the case. Every new piece of information we get is integrated with existing knowledge and in this way can strengthen rather than weaken what we already know.

Modern neuroscience has moved away from speaking of circumscribed “areas” dedicated to a single type of function, emphasising the importance of connections and dynamic networks. Research has shown that in people who can speak more than one language, activation of one language leads to activation of others. This richer pattern of activation requires higher levels of cognitive control and hence stimulates the development of better cognitive functions such as attention across the whole lifespan.

It is time that this knowledge reaches those who are responsible for the education of future generations.