Exploring the Emergence of Global‐Level J‐shaped Patterns From Local‐Level Dynamics in L2 Syntactic Complexity Development: A CDST Perspective

ABSTRACT Driven by the complex dynamic systems theory (CDST), this study explores how global patterns emerge from local dynamics in second‐language (L2) written language development. Forty‐one high‐school Chinese learners of English were tracked over one academic year. An integrative design and a person‐centered approach were adopted to combine the individual‐level and group‐level analyses. Four Syntactic Complexity (SC) features, i.e., overall length of production, sentential coordination, clausal subordination, and phrasal complexity, were employed. First, individual growth curve models (IGCM) revealed a J‐shaped or exponential development pattern: a gradual‐to‐rapid trend of acceleration over time, indicating the iterative process in which each stage of growth was built upon the previous one. Then, a time‐series cluster analysis identified two distinct profiles of learners with different growth rates, each exhibiting phase shift and interaction among the SC features. The paper ends with a discussion of how J‐shaped developmental patterns at the global level emerge from the dynamic mechanism at the local level in L2 SC development within the CDST framework.