Maria Konnikova:

In 1922, in “Tractatus Logico-Philosophicus,” the philosopher Ludwig Wittgenstein wrote, “The limits of my language mean the limits of my world.” The words that we have at our disposal affect what we see—and the more words there are, the better our perception. When we learn to speak a different language, we learn to see a bigger world.

Many modern language researchers agree with that premise. Not only does speaking multiple languages help us to communicate but bilingualism (or multilingualism) may actually confer distinct advantages to the developing brain. Because a bilingual child switches between languages, the theory goes, she develops enhanced executive control, or the ability to effectively manage what are called higher cognitive processes, such as problem-solving, memory, and thought. She becomes better able to inhibit some responses, promote others, and generally emerges with a more flexible and agile mind. It’s a phenomenon that researchers call the bilingual advantage.

For the first half of the twentieth century, researchers actually thought that bilingualism put a child at a disadvantage, something that hurt her I.Q. and verbal development. But, in recent years, the notion of a bilingual advantage has emerged from research to the contrary, research that has seemed both far-reaching and compelling, much of it coming from the careful work of the psychologist Ellen Bialystok. For many tasks, including ones that involve working memory, bilingual speakers seem to have an edge. In a 2012 review of the evidence, Bialystok showed that bilinguals did indeed show enhanced executive control, a quality that has been linked, among other things, to better academic performance. And when it comes to qualities like sustained attention and switching between tasks effectively, bilinguals often come out ahead. It seems fairly evident then that, given a choice, you should raise your child to speak more than one language. Indeed, papers touting “Creativity and Bilingualism,” “Cognitive Advantages of Bilingual Five-Year-Olds,” “A Bilingual Advantage in Task-Switching,” “Bilingualism Reduces Native-Language Interference During Novel-Word Learning,” and “Good Language-Switchers Are Good Task-Switchers”—and the resulting books with provocative titles such as “The Bilingual Edge” and “Bilingual Is Better”—suggest that raising a bilingual child is, in large part, a recipe for raising a successful child.