ABSTRACT
In this chapter second language (L2) learning is treated as an intellectualization process characterized by the internalization of L2 social speech and its potential culmination in the capacity to think verbally in the L2. This developmental process is seen through the lens of Vygotskyan sociocultural theory (SCT), a set of principles and hypotheses inspired in the work of Vygotsky and followers which allows for the observation of psycholinguistic development in ontogenesis (development over the lifespan). The focus will thus be on those processes leading to the development of the capacity to think through a new language which are related to the age of the learnernot as a biologically governed maturational factor, but as a function of radical psychological changes resulting from the interweaving of nature and culture in human development. In particular, the impact of learning a new language on the intellectual development of the individual at various stages throughout the lifespan will be addressed. This chapter will first lay out some basic general principles of SCT pertaining to cognitive and linguistic development and will then focus on what research has to say about the development of the faculty to think verbally in the L2, with particular reference to the age factor. The chapter will end with recommendations for research on insufficiently attended age-related issues of L2 development and pedagogical implications for the development of the L2 as a thinking tool among children and adults.
