6 BILINGUALISM AND THE BRAIN

There is a greater-than-chance probability that you, or your kids, or someone otherwise close to you speaks more than one language. The majority of the world's population is at least bilingual, and around 10 percent of all people speak three or more languages. We may call these people multilinguals, or polyglots, if they speak several languages fluently. This leaves monolinguals in the minority, albeit a sizable one at around 40 percent of people. The challenge for neurolinguistics is to develop theories and methods for testing such theories that apply to all speakers, not just to a (large) minority. That is why bilingualism is such an important research topic, not only in neurolinguistics but in language science at large.