Lesson‐to‐Lesson Fluctuations in Academic Self‐concept Driven by Self and Peer Achievements: An Intensive Longitudinal Study of Different Foreign Language Course Types

Abstract This study examines situational fluctuations in academic self‐concept (ASC) during English‐as‐a‐Foreign‐Language (EFL) learning, focusing on perceived self and peer achievements, and the moderating effects of course type. Using an intensive longitudinal method, 27 Japanese first‐year undergraduates completed surveys over 5 weeks after two EFL classes: General English and English Communication. Results from hierarchical linear modeling showed that perceived self‐achievement positively predicted situational ASC, consistent with previous findings. Perceived peer achievement decreased ASC in English Communication, reflecting the Big‐Fish‐Little‐Pond Effect (BFLPE), while it increased ASC in General English, reflecting the Basking‐in‐Reflected‐Glory Effect (BIRGE). Furthermore, the effect of perceived self‐achievement was stronger in the English Communication course than in General English. These findings underscore the situational and social nature of ASC, highlighting its variability across classroom contexts. The study also demonstrates the utility of intensive longitudinal methods in studying motivational constructs and provides insights into optimizing EFL learning environments, especially in interactive language classes.