Many people grow up in a bilingual home and/or community. A child’s brain is as capable of learning two languages as one. At one time people were fearful that growing up bilingual or trilingual would harm one’s brain—perhaps making one into an imbecile. Now, however, there is substantial research refuting such fears. Indeed, there is growing awareness of the benefits of this early childhood language-learning experience.
Here is an article that I think is well worth reading:
de Lange, C. (May 2012). Bilingual Brain Boost: Two Tongues, Two Minds. Published in New Scientist with the title: One brain, two minds. Retrieved 6/9/2012 from http://www.tumblr.com/tagged/catherine-de-lange.