As Eddie Izzard notes in the video above, the English, within our cosy, post-imperialist, monolingual culture, often have trouble coping with the idea of two languages or more jostling about for space in the same head. "No one can live at that speed!" he suggests. And yet, bilingual children seem to cope just fine. In fact, they pick up their dual tongues at the same pace as monolingual children attain theirs, despite having to cope with two sets of grammar and vocabulary. At around 12 months, both groups produce their first words and after another six months, they know around 50.
Italian psychologists Agnes Melinda Kovacs and Jacques Mehler have found that part of their skill lies in being more flexible learners than their monolingual peers. Their exposure to two languages at an early point in their lives trains them to extract patterns from multiple sources of information.
Kovacs and Mehler demonstrated that by sitting a group of year-old infants in front of a computer screen and playing them a three-syllable word. The infants could use the word's structure to divine where a cuddly toy would appear on the screen - if the first and last syllables were the same ("lo-vu-lo"), it would show up on the right, but if the first and second syllables matched ("lo-lo-vu"), it appeared on the left. By watching where they were looking, the duo could tell if they were successfully predicting the toy's position.
Success depended on learning two separate linguistic structures over the course of the experiment. The infants had to discern the difference between 'AAB' words and 'ABA' words and linking them to one of the two possible toy locations. After 36 trials where they got to grips with the concept, Kovacs and Mehler tested the infants with eight different words.
The bilingual ones were much better at it. For both groups of words - AAB and ABA - they initially glanced over to the correct side more often than the wrong one, and they fixed their gaze on it for longer. Monolingual babies only accomplished this for the AAB words - unlike their bilingual peers, they couldn't learn both linguistic rules at the same time.
When Mehler and Kovacs paired the ABA and AAB words with distinctly pitched female and male voices, even the monolingual infants managed to learn the differences between them. So while both sets of children can happily associate two speakers with two different types of word (and two screen positions), only the bilingual infants could learn two linguistic structures at the same time.
This advantage could stem from a better ability at avoiding interference between the two three-syllable constructions. Earlier this year, I wrote about other research from Agnes Melinda Kovacs and Jacques Mehler, who showed that infants raised in bilingual households have better executive functions - a catch-all term for advanced mental abilities that involve control, helping us to keep our goals and plans in mind while avoiding distraction from instinctive behaviours. These skills would certainly come into play when they tried to learn two separate languages at the same time.
Reference: Kovacs, A., & Mehler, J. (2009). Flexible Learning of Multiple Speech Structures in Bilingual Infants Science DOI: 10.1126/science.1173947
More on bilinguals and child development:
Five-month-old babies prefer their own languages and shun foreign accents
Babies' gestures partly explain link between wealth and vocabulary
Babies can tell apart different languages with visual cues alone
Deformed skull of prehistoric child suggests that early humans cared for disabled children
