This study investigated the developmental trajectories of three perceptual domains related to regional dialect competence: the linguistic domain, tested through an intelligibility in noise task; the objective indexical domain, tested through locality judgments and a free classification task; and the subjective indexical domain, tested through smart and friendly judgments. To allow direct comparison across domains, participants aged 4-71 years (N = 302) completed all tasks with the same talkers from four regional dialects of American English. The results demonstrated that development in each of these domains is protracted, with changes occurring as late as early adulthood. However, the developmental trajectories for each task and the connections between them differed significantly among the stimulus dialects. These dialect-specific patterns suggest that dialect perception requires extensive exposure to variety-specific linguistic and socio-cultural information, and the lengthy timecourse of sociolinguistic development reflects the substantial exposure that is necessary to successfully integrate linguistic and social information.