Book excerpt: This volume provides a broad coverage of the intersection of sociolinguistic variation and language acquisition. Favoured by the current scientific context where interdisciplinarity is particularly encouraged, the chapters bring to light the complementarity between the social and cognitive approaches to language acquisition. The book integrates sociolinguistic and psycholinguistic issues by bringing together scholars who have been developing conceptions of language acquisition across the lifespan that take into account language-internal and cross-linguistic variation in contexts of both first and second language acquisition as well as of first and second dialect acquisition. The volume brings together theoretical and empirical research and provides an excellent basis for scholars and students wanting to delve into the social and cognitive dimensions of both the production and perception of sociolinguistic variation. The book enables the reader to understand, on the one hand, how variation is acquired in childhood or at a later stage and, on the other, how perception and production feed into one another, thus building up our understanding of the social meanings underpinning language variation.