Journal of Sociolinguistics 14/4, 2010: 427–455 Coming of age in African American English: A longitudinal study 1 Janneke Van Hofwegen and Walt Wolfram North Carolina State University This study examines trajectories of development in the use of African American English (AAE) for 32 speakers through the first 17 years of their lives based on a unique, longitudinal database. Temporal data points in the analysis include 48 months, Grade 1 (about age 6), Grade 4 (about age 9), Grade 6 (about age 11), Grade 8 (about age 13), and Grade 10 (about age 15). Complementary methods of analysis for assessing AAE include a token- based Dialect Density Measure (DDM), a type-based vernacular diversity index, and frequency-based variation analysis. The study reveals different trajectories and peak periods for the use of AAE, including a ‘roller coaster’ and a curvilinear trajectory; at the same time, there is a common dip among speakers in the overall use of vernacular AAE from Grade 1 through Grade 4. Examination of a selective set of demographic and self-regard measures shows no significant differences for gender, school racial density, racial peer contacts, and measures of Afro-centrality, but does show a significant correlation between mothers’ and child use of AAE as well as age/grade. KEYWORDS: African American English, age-grading, language lifespan, language development, language change INTRODUCTION Although the vernacular structures of African American English (AAE) have been scrutinized in great detail over the last half-century, there remain a number of questions about the development and use of these structures during the lifespan of AAE speakers. Is there a period in the life cycle when the vernacular structures are most likely to be evidenced, and if so, when? How much variation in vernacular usage may be demonstrated from childhood through adolescence, and do children show similar or different trajectories of vernacular dialect development and change over time? What social and structural linguistic factors influence these trajectories? Although many of the canonical studies of AAE (e.g. Labov, Cohen, Robins and Lewis 1968; Wolfram 1969; Fasold 1972; Rickford 1999) have considered the correlation of age with vernacular dialect variables, these questions have persisted since the early descriptive studies almost a half- century ago. C  Blackwell Publishing Ltd. 2010 9600 Garsington Road, Oxford OX4 2DQ, UK, and 350 Main Street, Malden MA 02148, USA