Mobile Devices and Social-Emotional Development: School Engagement as Mediator and Its Compensation for Left-behind Children in China

Digital transformation has fundamentally reshaped educational landscapes and profoundly influences youth development post-COVID-19, particularly affecting vulnerable populations like left-behind children (LBC). This study investigates how adolescents' mobile device use influences their social-emotional learning (SEL) competencies through school engagement, examining differential patterns between LBC and non-LBC. Through structural equation modeling (SEM) of data from 405 junior secondary school students (201 LBC) in rural China, this study analyzed four device-related factors: usage frequency, attitudes, adult supervision, and technoference (technology interference). Results demonstrated that technology's developmental influence operated primarily through school engagement mediation, with technoference emerging as the primary risk factor (total effect = -0.341) and supervision showing consistent protective effects (total effect = 0.228). The mediation patterns demonstrated heightened intensity among LBC, particularly for technoference (β = -0.428 vs -0.261) and supervision (β = 0.293 vs 0.142), suggesting increased vulnerability coupled with enhanced responsiveness to protective factors. Despite family separation and LBC's higher mobile phone reliance (t = 2.166) and decreased SEL competencies (t = -2.701), school engagement exhibited compensatory effects by maintaining developmental trajectories. While behavioral engagement showed group differences, affective and cognitive dimensions remained stable, indicating that family separation primarily affects engagement manifestation rather than underlying educational connection. These findings advance understanding of how digital experiences transfer between home and school while highlighting educational institutions' potential compensatory role in stabilizing developmental trajectories for vulnerable populations. The findings advocate coordinated interventions to leverage technology's potential while supporting diverse family structures in increasingly digital learning environments.