Bilingual children might have a superpower, UT study finds

"Children who grow up hearing their parents switch back and forth between languages are strengthening mechanisms that are critical to executive function, even before they are able to produce their first word.”

AUSTIN (KXAN) — A yellow smiley face bounces around a flat screen TV as a mesmerized toddler sits in front. He's wearing a cap that cradles his head, attached to a bundle of wires.

The baby seems impossibly calm as UT Associate Professor Maria Arredondo conducts this experiment — one she's already done on over 100 children. 

In a study published in March, Arredondo revealed how bilingual infants from 6 to 10 months old think and learn differently from those who grow up in monolingual households.

Even before their first words, bilingual children are already able to differentiate languages, she showed. This unique skill allows bilinguals to strengthen parts of the brain that are essential to managing behavior and planning.

Inside the study

Puppets, bubbles and dancing smileys may seem like playful distractions, but they are actually key to testing memory and attention. The wired cap is covered in electric sensors which send hundreds of painless infrared lights into the brain to monitor its activity.

Arredondo found bilingual children perform the tasks at the same level as monolinguals. The difference is, bilinguals use a different part of their brain to do so.

"While the monolinguals were using the right frontal region of the brain, which typically engages attention, bilinguals were activating their left frontal region more," Arredondo said. "What’s fascinating is that the left frontal region is associated with language processing."

In other words, bilinguals engage the same part of the brain that differentiates between two languages to perform non-language-related tasks. 

Why do bilinguals think differently?

"Code-switching between different languages is very typical in bilingual households," Arredondo said. "So children who grow up hearing their parents switch back and forth between languages are strengthening mechanisms that are critical to executive function, even before they are able to produce their first word."

These mechanisms Arredondo refers to are "attention" and "inhibition."

To better understand, take a look at the illustration below.

Do you see a man? Or a mouse? With some effort, you can likely see both. 

This type of image is called an ambiguous figure. Our interpretation of the figure can switch based on our attention to different details. When our attention is focused on the man, we are inhibiting the image of the mouse, and vice versa.

A bilingual child may have an easier time switching between the two images, because they have more practice engaging parts of the brain used to code-switch languages. 

Arredondo said the brain is like a muscle, so the more you stretch it from early infancy, the more cognitively flexible you're likely to become later on.

"So very early on, even before they're able to produce the first word, their brain is adapting to their environment," Arredondo said. "This shows that the brain is highly plastic."

But how do infants even know the difference between two languages?

For a long time, experts assumed that introducing different languages to early infants would confuse the child, causing a delay in developmental milestones.

But research shows the opposite is actually true.

Each language has an average of about 40 different sounds or "phonemes" associated with their vocabulary. These phonemes are how we distinguish one language from another.

At birth, an infant's brain has a special superpower: they are able to perceive the entire range of phonemes belonging to every language in the world. This allows an infant to learn any language they are exposed to in the womb and after birth.

Other ways infants are able to distinguish two languages are through observing the rhythms, syllable stresses and mouth movements of those who are speaking.

As a child gets older, however, their perceptual window of phonemes narrows. The later a child is introduced to a second language, the more likely it is that they will have trouble neutralizing a perceptible accent and differentiating the sounds.

Growing up bilingual

Arredondo’s interest in studying bilinguals grew out of her personal curiosity. She grew up speaking Spanish in Argentina before moving to the U.S. at 12 years old.

"While my younger brother had an easy time learning English, I always wondered why my parents and older sister struggled," Arredondo said.

While Arredondo's study suggests the benefits of learning two languages from infancy, acquiring a second language later on in childhood can be more challenging.

Former Bilingual Literacy Specialist for Austin ISD Susana Alverdi spoke to the difficulties that English-language-learner students face in the public school system, particularly.

"I've had bright students that were so excellent in my bilingual class, where we spoke Spanish and English, but they were immediately moved to English-only classes, where they become a very mediocre student. They struggled. This should have been a smoother transition," Alverdi said.

More than 20% of Texas students are enrolled in English as a Second Language (ESL) programs, and that number is increasing every year. Yet, a recent Rice University study showed that Texas is only getting worse at teaching students English.

Researchers found the percentage of ESL students who fail to become proficient in the language is increasing — a problem that the pandemic only exacerbated due to teacher shortages.

Alverdi thinks schools could ease the transition to English-only education by doing more to accommodate bilingualism in homework assignments and standardized testing.

Celebrating bilingualism

A decade ago, Alverdi left public education to found a Spanish-immersion preschool in Austin, Atelier Preescolar, with her daughter, Alexa.

They hope that by teaching children Spanish as early as 12 months old, they can normalize bilingualism in the classroom setting.

Alexa, who is now director of the preschool, says that learning a language as prevalent in Texas as Spanish can help children develop more cultural awareness and empathy.

"A bilingual child, at a very young age, is developing their theory of mind, which is how we understand another person's needs as different from our own. You learn that you may need to switch the language you are using for someone else to understand you," Alexa said.

Miranda Gale, who demonstrated Arredondo's lab test with her toddler, Zephyr, said she decided teaching her son Spanish was socially necessary.

"We wanted the opportunity to learn Spanish, and it just felt like the best thing to do for him, so that he could have as many opportunities for connection as possible in his life," Gale said.

As more bilingual preschools and language immersion programs crop up around Austin, Alverdi hopes more parents can introduce their children to other cultures.

"Here in Austin, in the 90s, I grew up in a predominantly white area, and there was not a lot of people for me to speak Spanish with," Alexa said. "At that time it definitely was not easy to grow up bilingual because you kind of are battling between two cultures. But the more I leaned into it, the more I embraced it as a gift."

With her findings, Arredondo aims to encourage more parents to introduce a second language as early as possible.

"Do not be afraid to teach your child other languages, especially if you want to teach them your heritage language," she said.

If you would like to participate in a study at UT's child learning and development lab, you can sign up here.