Working Memory Development: Cross-Sectional and Longitudinal Analyses of Primary School Children in an Adaptive Learning Environment

The present study investigated the spatial working memory (WM) ability and its developmental change, utilizing large-scale cross-sectional and longitudinal data from an adaptive learning environment. Approximately 16% of Dutch primary school children participated in a spatial serial recall task between 2019 and 2025, providing dense, continuous measurements of the same children in their regular educational environment. Cross-sectional analyses demonstrated the increase of working memory capacity between the ages of six and twelve on average by one item. However, the spatial complexity of the lists affected this capacity increase. Moreover, longitudinal analyses of accuracy demonstrated WM ability maturation over time, yet there was no impact of practicing the task. Furthermore, significant individual differences were observed among children. Future studies should focus on a better assessment of spatial complexity and the underlying sources for individual differences in WM development.