Book excerpt: Language acts are acts of identity, and linguistic variation reflects the multifaceted construction of verbal alternatives for transmitting social meaning, where style-shifting represents our ability to take up different social positions due to its potential for linguistic performance, rhetorical stance-taking and identity projection.Traditional variationist conceptualizations of style-shifting as a primarily responsive phenomenon seem unable to account for all stylistic choices. In contrast, more recent formulations see stylistic variation as initiative, creative and strategic in personal and interpersonal identity construction and projection, making a significant contribution to our understanding of this aspect of sociolinguistic variation. In this volume social constructivist approaches to style-shifting are further developed by bringing together research which suggests that people make stylistic choices aimed at conveying (and achieving) a particular social categorization, sociolinguistic meaning, and/or to project a specific positioning in society. Therefore, there is a need, we collectively argue, to adopt permeable and flexible multidimensional, multidisciplinary and interdisciplinary approaches to speaker agency that take into consideration not only reactive but also proactive motivations for stylistic variation, and where individuals – rather than groups – and their strategies are the main focus when examining style-shifting in public. This book will be of interest to advanced students and academics in the areas of sociolinguistics, dialectology, social psychology, anthropology and sociology.