Written by the world-renowned pioneer in the field of modern sociolinguistics, this volume examines the cognitive and cultural factors responsible for linguistic change, tracing the life history of these developments, from triggering events to driving forces and endpoints. * Explores the major insights obtained by combining sociolinguistics with the results of dialect geography on a large scale * Examines the cognitive and cultural influences responsible for linguistic change * Demonstrates under what conditions dialects diverge from one another * Establishes an essential distinction between transmission within the community and diffusion across communities * Completes Labov's seminal Principles of Linguistic Change trilogy