Bilinguals slower to build vocabulary but better at multitasking.
Children who grow up learning to speak two languages are better at switching between tasks than are children who learn to speak only one language, according to a study funded in part by the National Institutes of Health. However, the study also found that bilinguals are slower to acquire vocabulary than are monolinguals, because bilinguals must divide their time between two languages while monolinguals focus on only one.
In the study, bilingual and monolingual children were asked to press a computer key as they viewed a series of images — either of animals or of depictions of colors. When the responses were limited to either of the two categories, the children responded at the same speed. But when the children were asked to switch, from animals to a color, and press a different button for the new category, bilinguals were faster at making the change than were the monolinguals.
Researchers often use this switching task to gauge a set of mental processes known as executive functioning—generally defined as the ability to pay attention, plan, organize, and strategize. The task engages three mental processes: the ability to keep a rule or principle in mind (working memory), inhibition (the ability to refrain from carrying out one rule), and shifting (the ability to make the change and act on another rule).