the research

Ellen Bialystok, a professor of psychology at Toronto's York University and a leading researcher in the fields of bilingualism and cognition, has studied bilinguals for two decades and has a balanced view of the issue. "There is a lot of fear that exposing children to languages will cause confusion and harm," she observes. "Then there is all this hyperbole about incredible advantages—people who claim children who learn two languages will have higher IQs and better academic success. Neither view is correct."

According to Bialystok, there is "not a shred of evidence" of bilingualism causing confusion. Instead, she says, when kids use languages in a mixed way, "they show how clever they are in taking advantage of all the things they know how to communicate," using whatever linguistic tools are available to them. Studies of 2- to 4-month-old babies have found that they send out different brain signals in response to each language. In fact, the closer we are to birth, the better we are at discerning phonetic contrasts between languages. "Way before these children learn to speak, they understand that different languages are different systems," Bialystok says. "If they are not confused by two, they won't be by three." This also answers the old question about how soon children should be exposed to languages: never soon enough.

Researchers have confirmed that bilinguals (children and adults) can find it hard to retrieve words as quickly as their monolingual counterparts do. They tend to score lower than others on semantic-fluency tests, in which subjects are asked to do things like list as many animals as they can think of in 60 seconds. Studies have also shown that bi- and multilingual children start to speak slightly later than monolinguals, with a smaller pool of words. But while they may have a restricted vocabulary in each language, they do not have a smaller overall vocabulary. Over time, they catch up.

Such handicaps are a small price to pay when you consider bilinguals' cognitive strengths. Control of attention tops the list: They find it easier to stay focused, especially when confronted with inconsistent information. When psychologists show children cards that look like, say, a rabbit at first glance, then a duck after a closer look, most kids 7 and under can't change their minds once they've locked in on an interpretation. Bilinguals are less prone to this problem. "They see things in different ways and can more easily switch back and forth," says Bialystok. "It's good preparation for today's multitasking world."

In another study cited by Bialystok, monolinguals and bilinguals were asked to work on a computerized simulation of a basic everyday task: setting the table while cooking breakfast. The groups prepared the meal equally quickly, but they differed in how well they alternated between the activities. Bilinguals found it easier to interrupt their cooking and got further along with the secondary task.

And they also do well on the Stroop test, which asks subjects to view internally contradictory cards—one on which the word blue is written in red ink, for instance. Monolinguals have a harder time correctly naming the color. Such information-sorting abilities are applicable to many tasks later in life that involve planning and organizing. The mental process of sorting takes place in the front part of the brain, which is the last to develop in babies. Research has found that when it comes to such frontal-lobe "executive" functions, bilingual children are often capable of doing at 4 years what monolinguals can't until they're 5.

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