The significance of peer relationships for executive functions and learning outcomes

This PhD thesis examines the effects of peer exclusion on working memory and academic achievement across childhood and adolescence. Peer exclusion (being ignored or left out of activities, play, or conversation; Riva & Eck, 2016)—is pervasive in schools, yet its impact on executive functions such as working memory(Miyake et al., 2000) remains underexplored due to the lack of ecologically valid paradigms across age groups (Parsons, 2015; Tuijnman et al., 2021), limited research on immediate versus daily effects (Dirk & Schmiedek, 2016; Galeano-Keiner et al., 2022), and insufficient integration of emotional and cognitive outcomes in developmental trajectories (Vandenbroucke et al., 2018; Fuhrmann et al., 2019). Grounded in Ecological Systems Theory (Bronfenbrenner, 2005), Attachment Theory (Bowlby, 1969, 1982), and Self-Determination Theory (Deci & Ryan, 1985), the PhD thesis investigates how immediate episodes (i.e., short-term effects observable right after an event) and daily fluctuations (i.e., fluctuations in experiences across days in natural school settings) in peer exclusion affect students’ working memory and academic success. Together, the PhD thesis shows that peer exclusion has both immediate emotional and cognitive consequences and dynamic day-to-day effects on working memory and perceived academic success. These effects are moderated by developmental stage as well as by contextual and individual factors. By integrating immersive VR paradigms with intensive longitudinal studies, this dissertation advances the study of peer exclusion methodologically, theoretically, and practically, offering a more nuanced understanding of its role in learning and development.