Independent regulation of cognitive stability and flexibility in both intra-task and inter-task contexts among children

Stability and flexibility are essential components of cognitive control, critical for goal-directed behavior and adaptability, particularly in children. However, the relationship between them is debated; traditional unidimensional models suggest a trade-off relationship, while recent studies propose a two-dimensional perspective emphasizing their independence. Previous research mostly focused on adults, overlooking the rapid development of stability and flexibility in children. The current study recruited 38 adults and 73 healthy children aged 9–10 years to investigate the relationship between stability and flexibility in both intra-task (Experiments 1 and 2) and inter-task (Experiment 3) contexts. Experiments 1 and 2 utilized a rule-switching task with stimulus-response consistency manipulation: switch costs measured flexibility, while the consistency effect assessed stability. Both results of Experiments 1 and 2 supported a two-dimensional model for cognitive stability and flexibility in the intra-task context. Experiment 3 employed the color-word Stroop task to measure cognitive stability (congruency effect), and an inter-task correlational analysis was conducted with the switch costs (flexibility indicator) from Experiment 2. The findings revealed no significant correlation between the Stroop congruency effect and rule-switching costs, indicating independence between stability and flexibility in different task contexts, further supporting the two-dimensional model in the inter-task context. In conclusion, this study supports the independence of cognitive stability and flexibility during middle childhood, demonstrating their ability to coexist at high levels based on task demands. These insights deepen our understanding of cognitive control in children and provide a theoretical foundation for offering developmental guidance and developing effective cognitive training programs.