This project proposes to combine for the first time historical (socio)linguistics with the insights from modern psycholinguistic research to study linguistic variation in post-Classical Greek. For this purpose the study will use the corpus of Greek documentary papyri, an important source for our knowledge of the history of Greek after the Classical period (ca. 300 BCE – 800 CE). The project builds on existing infrastructure developed by the applicant in previous projects, namely an annotated database of scribal variation and the original corrections by ancient scribes: a new valuable, but still largely unexplored resource. Important principles in language processing and production, which have not been studied in this corpus before, will be examined at the level of writing, spelling and morphology by means of a quantitative and qualitative corpus analysis, and compared to relevant social factors, such as individual competence, production circumstances and the community of practice. This new knowledge on the social and cognitive processes involved in the production of the most frequent orthographic interchanges will contribute to our understanding of variation and change in the history of the Greek language. By integrating this novel psycholinguistic perspective into the field of historical (socio)linguistics, this project will also contribute to a more comprehensive usage-based theory of language variation and change in historical linguistics.