The Corner


Bilingualism Makes You Smarter — Or Not

The progressive demonstration with the strange name “March for Science” is scheduled for this weekend. Although organizers call it “the first step of a global movement,” the march actually continues a long tradition of activists invoking science as a cover for positions that are fundamentally ideological. As Heather Wilhelm observed last week, “This March for Science does not appear to be largely about science, or about people who know a great deal about science, or even about people who want to know a great deal about science.”

How did we get to the point where science is a political buzzword for progressivism? Part of the problem is that scientists are people too, and they are subject to the same pressures and biases as anyone else in the public sphere. Perhaps for that reason, research has a tendency to offer “objective” support for ideas that have become politically fashionable.

I encountered an example recently while putting together an essay for The American Conservative on the spread of bilingualism. Whether to encourage immigrant families to retain their ancestral language is a value-laden question involving the larger ideological conflict between multiculturalism and assimilation. Bilingual advocates, however, offer a scientific argument for their position: It makes people smarter. As California’s new bilingual-education law states, “A large body of research has demonstrated the cognitive, economic, and long-term academic benefits of multilingualism and multiliteracy.” How convenient for multiculturalists!

As I detail in the essay, the claim that bilingualism improves cognitive function has fallen victim to the “replication crisis”:

In a profession that rewards novelty, academics and the journals that publish them often take even the slightest hint of a positive finding and run with it, downplaying or ignoring null results. Since researchers have become increasingly interested in large-scale replications in recent years, they have had trouble verifying some of the most well-known results in social psychology.

The alleged link between executive [cognitive] function and bilingualism is no exception. Writing in the academic journal Cortex in 2016, psychologist Kenneth Paap recalled how he and his colleagues initially “had strong expectations that we would replicate a strong advantage” for bilinguals on executive tasks. But they couldn’t. “Three studies, three additional tasks, and 273 participants later we reconsidered the hypothesis and . . . what changed our mind was simply the weight of the evidence.” Many psychologists are no longer convinced that bilingualism improves executive function at all. Given the state of the evidence, there is no clear case for encouraging bilingualism in the U.S. on cognitive grounds alone.

I did not have space to mention that “bilingualism makes people smarter” is itself a reversal in the literature. Before the 1960s, the opposite view predominated. “The general trend in the literature relating to the effect of bilingualism upon the measure of intelligence, has been toward the conclusion that bilinguists suffer from a language handicap,” according to a 1953 review paper [pdf]. So at a time when assimilation was the prevailing ideology among political elites, science told them bilingualism is bad for the mind. Later, when multiculturalism became the prevailing ideology among elites, science told them bilingualism is good for the mind. Which is the cause and which is the effect here?

Thank goodness for the replication crisis and the renewed interest in scientific transparency that has come along with it. If there were a March for Large-Scale Preregistered Replications, I would be on the front lines.


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