Abstract: College freshmen navigating early adulthood experience a critical phase of social role reconstruction, facing new challenges in interpersonal adaptation and environmental integration. While previous studies have examined the relationship between social media use and interpersonal adaptation among college students, these have predominantly employed cross-sectional or long-term longitudinal designs, making it difficult to capture the daily, real-time dynamics between these variables during freshmen’s first month at college. Furthermore, the mechanisms underlying this relationship, as well as its boundary conditions within intensive time frames, remain underexplored. Therefore, using the first month of attending college as a temporal window and employing the residual dynamic structural equation model (RDSEM), this study examined the fine-grained temporal associations between social media use and interpersonal adaptation. It further investigated the intensive mediating effect of self-concept clarity and the cross-level moderating influence of envy.
A 30-day intensive longitudinal survey was conducted among 306 freshmen during their first month of college (M_age = 18.18 years, SD = 0.63; 71.9% female). Every day at 8:30 p.m., participants received an online questionnaire that they had 30 min to complete. If no response was received within 20 min, the system automatically sent a reminder, and the questionnaire closed 10 min thereafter. On average, participants spent approximately 5 min completing the survey daily.
RDSEM analyses were conducted via Mplus 8.7 and used to examine the fine-grained cross-lagged effects among the variables and a moderated mediation model. The results provided three major insights. First, social media use at time t - 1 significantly and negatively predicted the interpersonal adaptation of freshmen at time t. Second, social media use at time t - 1 significantly and negatively predicted self-concept clarity at time t, which in turn positively predicted the interpersonal adaptation of freshmen at time t + 1. Third, freshmen with high levels of envy were particularly susceptible to the negative effects of social media use at time t - 1. This susceptibility manifested in low interpersonal adaptation at time t + 1 and a marked decline in self-concept clarity at time t.
These findings indicate that the adverse effects of social media on interpersonal adaptation can be mitigated by guiding freshmen to appropriately regulate their social media use during the initial stage of college and to cultivate an integrated and stable self-concept. In addition, freshmen with high levels of envy should be identified as a key group for targeted support, thereby helping reduce their tendency to perceive others’ positive self-presentations on social media as threats. Overall, by investigating the mechanisms underlying the negative effects of social media during the early college adjustment period, this study offers practical insights for promoting smoother adaptation among freshmen in the modern digital environment.

Key words: social media use, interpersonal adaptation, self-concept clarity, envy, residual dynamic structural equation model