Moving beyond two languages The effects of multilingualism on language processing and language learning

rom diplomatic negotiation to translation of foreign communications to interpreting in conflict zones, language skills are vital to national security. Because it is sometimes difficult to predict which languages will be of strategic importance in the future, U.S. Government agencies need to select and train personnel in new languages as quickly as possible. A common strategy is to identify personnel who are already working in a foreign language and train them in a new language, an approach known as cross-training, which includes conversion.1 Research on cross-training per se is very limited and consists primarily of a few documented cases of cross-training courses that were shorter than regular courses but produced similar results. The currently available evidence from the fields of psycholinguistics and Second Language Acquisition (SLA) suggests that multilingual learning can be affected by an individual’s cognitive control and overall proficiency in previously learned languages, and that previous linguistic knowledge and language learning experience can also affect the individual’s learning of consecutive languages. In particular, it has been documented that language similarity of the L3 to any known language may improve learning. However, little is known about specific ways to achieve successful cross-training via multilingual pedagogy. The goal of the current report is to open a new avenue of investigation by considering multilingual cross-training issues from a psycholinguistic perspective by reviewing the existing literature on the processing and acquisition of multiple languages. Over the last 30 years, a growing body of psycholinguistic research has been devoted to the study of bilingual language processing and second language (L2) acquisition. Although the term “L2” is often used in the scientific literature to refer to any language other than one’s native tongue (L1), relatively little research has focused on issues that are specific to learning or processing a third language (L3) or beyond. In this report we review existing research on the psycholinguistic and cognitive factors that may affect the learning and use of languages beyond the L2. Before we begin, it is important to clarify terminology: