This expansive, longitudinal study constitutes a major contribution to the ongoing debate over age in SLA. Through careful and sophisticated analyses, Pfenninger and Singleton present convincing evidence that late SLA confers specific linguistic, cognitive and affective advantages. Practitioners, policy makers and researchers alike will find many new insights here from which to question the 'earlier is better' mantra. * Alene Moyer, University of Maryland, USA * This book makes a major contribution to the field of instructed second language learning. Paying particular attention to methodological issues, the book goes beyond age effects to show the multiple ways in which internal and external factors may affect the learners' processes and outcomes. The book also provides very rich and timely insights for foreign language education. * Carmen Munoz, University of Barcelona, Spain * This is a balanced and perceptive study that approaches a topic of interest to us all, drawing on fresh evidence and careful analysis. The authors investigate the impact of both learner-internal and -external factors applying state of the art statistical modelling, and their results are of great relevance for both researchers and policy makers. * Raphael Berthele, University of Fribourg, Switzerland *