Adaptation to the School Environment Moderates the Effect of Skill‐Specific Performance on Pupils' School Achievement in the First Grade of Elementary School

ABSTRACT The transition from kindergarten to the first grade of elementary school is a crucial developmental period that can significantly influence pupils' academic trajectories. This study aimed to examine whether adaptation to the school environment moderates the relationship between skill‐specific performance and academic achievement in two core subjects—Czech language and mathematics. A longitudinal design was employed involving 702 first‐grade pupils, with assessments focusing on specific academic skills, overall school achievement, and two dimensions of school adaptation: adaptation to performance demands and adaptation to school rules. Robust statistical methods, including MM‐type regression and moderation analysis, were applied. Results showed that in Czech language, reading and writing skills significantly predicted achievement, while language skills alone did not. In mathematics, the application of numerical operations in word problems and visuospatial abilities had the strongest predictive effects, whereas basic numerical knowledge had no significant impact. Crucially, both aspects of adaptation to the school environment moderate these relationships, with stronger adaptations enhancing the impact of specific skills on academic achievement. These findings directly support that adaptation to the school environment moderates the relationship between skill‐specific performance and academic achievement. The results show that stronger adaptation—both to performance demands and school rules—amplifies the impact of students' reading, writing, and problem‐solving skills on academic success in Czech language and mathematics.