Multimodal Corpus-Based Studies of Language Development: A Plea for Lifespan Linguistics

While language development unfolds across the entire lifespan, mainstream research has long focused on isolated age stages, fostering theoretical gaps that mask its continuous dynamics. To bridge this divide, we propose Lifespan Linguistics , a holistic framework rooted in Complex Dynamic Systems Theory (CDST), that leverages multimodal corpus-based methods to trace the interplay of biological, cognitive, and socioemotional influences over time. This paradigm facilitates detailed mapping and causal analysis of nonlinear trajectories from infancy to old age, laying the groundwork for evidence-based tools in screening, assessment, and intervention tailored to developmental norms. Moving beyond cross-sectional studies, this study develops an integrated, multimodal corpus-based framework that synergistically supports descriptive, explanatory, and applied research on lifespan language development. By capturing multimodal communication in ecological settings, this paradigm advances both theoretical understanding and practical applications for supporting language well-being across the life course.