From visual presence to communicative readiness: unpacking the chain mediation of social cues on L2 willingness to communicate in synchronous online classrooms

While online second language (L2) platforms offer flexibility, generating active communication remains a persistent challenge. Guided by the Cognitive–Affective-Social Theory of Learning in digital Environments (CASTLE) and the heuristic pyramid model of Willingness to Communicate (WTC), this study investigated the mechanism through which social cues (SC) influence L2 WTC using an explanatory sequential mixed-methods approach. Participants were 249 English as a Foreign Language (EFL) learners in Chinese junior high schools. Structural equation modeling revealed that social cues did not directly affect L2 WTC. Instead, they exerted a significant indirect influence through three pathways: the mediation of attitude/motivation, the mediation of engagement, and the chain mediation of attitude/motivation and engagement. The qualitative phase, involving interviews with 15 students, was conducted to explain these statistical findings. Thematic analysis identified key mechanisms such as social cues as a motivator to communicate, social cues as a trigger for communicative engagement, digital context barriers, and overcoming barriers through internal drive. These findings provide empirical support for the CASTLE framework in the SLA domain by unveiling the mechanism through which social cues influence L2 WTC. Some specific pedagogical implications are provided to enhance the instruction design and classroom management in synchronous online context.