In cognitive psychology, researchers have identified a phenomenon called socially shared retrieval-induced forgetting (SS-RIF) that occurs during collaborative memory tasks in groups. When a speaker selectively retrieves target information, listeners may forget related, non-target information. The mechanism likely involves concurrent covert retrieval. Relational motivation is a key factor, particularly when the speaker is an in-group member, which enhances listeners' covert retrieval and results in SS-RIF. Although prior studies on relational motivation mainly focus on adults, the impact of teacher-student and peer relationships on middle school students during a critical cognitive development phase remains largely unexplored. This study aimed to examine the influence of relational motivation on SS-RIF in middle school students, expanding on existing literature. In Experiment 1, the independent variables were speaker identity (teacher vs. peer) and item type (Rp + , Rp-, Nrp + , Nrp-), while the dependent variable was the correct recall rate in the final retrieval phase. Results showed that SS-RIF occurred only when middle school students acted as speakers. A replication study was conducted to ensure the reliability and generalizability of these findings. The findings confirmed the influence of student speaker identity on SS-RIF in middle school students, highlighting the importance of relational motivation in collaborative memory. These results extend previous research and provide a theoretical basis for enhancing cooperative learning among middle school students.