Individual differences and community-level constraints on sociolinguistic variationLaurel MacKenzieDepartment of Linguistics, NYUThe traditional focus of variationist sociolinguistic research is the patterning of language variation at the level of the community, which individual language users are said to learn and reproduce (Labov 1972; 2012). Studies in which constraints on variation are examined at the individual level find that individuals match the pattern shown by their community with remarkable consistency (Guy 1980, Meyerhoff & Walker 2007, Forrest 2015). In this talk, I examine two sources of counterexamples to this individual-level consistency. Differences in the mental representations speakers have for a form, and differences in speech production planning abilities, can both lead individuals to diverge in their constraints on a variable from the community-level pattern.I then address whether these individual-level differences can actuate community-level change, in the same way that individual differences in speech production and perception have been suggested to actuate community-level sound change (e.g. Baker et al. 2011, Stevens & Harrington 2014, Mielke et al. 2016). I demonstrate that, suggestively, there are cross-community differences in constraints on variation that resemble the individual-level differences previously presented. The talk thus brings together two different areas of research — mechanisms of sound change and comparative sociolinguistics — to address broader questions of the production of sociolinguistic variation, the understanding of community grammars, and the nature of language change.