Why do you talk the way you do? You’ve lived somewhere—perhaps many somewheres. Your friends or family have influenced you. You’ve probably even thought about how you like some linguistic features and want to avoid others. People have long been aware that these factors influence why different groups speak differently, but the systematic study of dialect began in the eighteenth and nineteenth centuries, as part of the same scientific movements that gave us the Linnaean catalogue of the living world and the periodic table of the elements.