Keeping it together: Hourly dynamics of children's behavioral regulation at school in a decades-long cohort study

Though theoretical accounts describe self-regulation as dynamic, empirical studies typically rely on static measures that fail to capture changes in self-regulation from day to day or moment to moment. As a result, little is known about how children's self-regulation may fluctuate within person, despite clear relevance for educators. In this article, we capitalized on repeated observations from wearable devices to test the idea that daily increases in activity across the school day could reflect a school-aged child's inability to regulate their physical activity to be appropriate to the school setting. In a national sample followed from birth to age 26 (N = 747; 49% female; 76% White, 13% Black, 6% Hispanic, 5% Other), children showing daily increases in activity (greater daily increases in activity) in third grade, objectively measured using actigraphy at school and charted across hourly intervals, were rated as more impulsive and disruptive by teachers and classroom observers and showed lower academic achievement in third grade (β = -0.13), which mediated indirect associations to achievement in high school (β = -0.11) and fewer years of education completed as adults (β = -0.05). Findings suggest that children's behavioral regulation, proxied by the ability to inhibit motor activity, deteriorates across the school day and that children who can sustain behavioral regulation for longer achieve greater educational success. Findings also reveal temporal patterns of behavior in third grade that motivate future investigations into daily experiences that could restore children's behavioral regulation. (PsycInfo Database Record (c) 2026 APA, all rights reserved).