The news: There are many intangible yet obvious benefits to bilingualism: Language skills are increasingly valuable in a globalized job market, and those who speak multiple languages have greater access to other cultures. But while this ability has previously been associated with improved cognitive function, we haven't had much proof that bilingualism truly affects the brain in a positive way — until now.
A study published this week in Annals of Neurology announced an incredible finding: Researchers had been able to link bilingualism with slower cognitive decline later in life.
"Our study is the first to examine whether learning a second language impacts cognitive performance later in life while controlling for childhood intelligence," lead author Thomas Bak, of the University of Edinburgh, said in a press release. "Our study shows that bilingualism, even when acquired in adulthood, may benefit the aging brain."
How was the study conducted? The research took place over decades as a group of 835 native English speakers in Scotland were surveyed. The participants took an intelligence test in 1947 and again between 2008 and 2010. The homogeneity of the group helped to rule out potentially influential factors, such as ethnicity and immigration status.
Of the participants, 262 reported that they spoke another language; among them, 195 said they learned it before age 18, while 65 said they learned it afterward. When they were in their 70s, the participants were asked to take an intelligence exam to test their verbal reasoning, vocabulary and reading abilities, verbal fluency and ability to process information quickly. And what researchers found was remarkable.
The result: Participants who said they spoke a second language performed much better than their baseline cognitive ability — those who said they spoke three languages or more did even better. The effect of speaking multiple languages was comparable to "the effect of variation in the gene for apolipoprotein E (which is linked to Alzheimer's), physical fitness and (not) smoking," the authors wrote.
A factor that could have influenced the study's result is the possibility that multilinguals are a self-selecting group: It might be that people with healthier brains are more likely to learn or practice another language. But even accounting for early intelligence test results, researchers found a consistent link between linguistic ability and cognitive function.
"Probably the causality is going in both directions, but we showed that there is certainly an effect of bilingualism that cannot be explained by previous differences," Bak told Reuters.
So while learning another language is certainly not the definitive solution to prevent cognitive decline, it is still very much helpful. Perhaps it's time to take a look at your dusty college Spanish textbook again.