In sports, it is crucial to adapt to errors of teammates to achieve a good performance. However, despite the large literature on social error monitoring, the social error monitoring processes of athletes and coaches have received little attention. Moreover, the mechanisms underlying the processing of observed errors are still debated. A crucial factor which can shed further light on these theoretical accounts, is the relationship between actor and observer. The team-sport context offers a unique opportunity to test the effect of this relationship on social error monitoring, since team-affiliation allows to distinguish teammates from other athletes. In this project we will systematically investigate how a team-relationship influences detection of, adaptations to and neural responses following observed errors. We will investigate both athlete-athlete and coach-athlete relationships, to investigate the effect of different types of sport relationships. This project focusses specifically on basketball, since the shot-structure in basketball allows for a good operational definition of errors which is one of the difficulties associated with studying error monitoring in sports. Understanding the error monitoring processes of athletes and coaches, is informative for both the world of sports and the theoretical accounts on social error monitoring.