More than one language: Cognitive perspectives and implications for language policy

For several decades, research has shown that bilingualism, especially early bilingualism, has both linguistic and cognitive benefits on human development over the lifespan. This chapter discusses studies both in favour of and against this account. We further present the possible implications that the effects of bilingualism involve for language policy and planning. In the last section of this chapter, we address specific needs of bilingual speakers with an atypical language development to foresee a range of actions and plans that might be adopted for a complete bilingual growth in a vulnerable population.