Sleep Duration and Kindergarten Adjustment

OBJECTIVES: The current study examined longitudinal linkages between child sleep duration and children's socioemotional, learning engagement, executive functioning, and academic outcomes across the full kindergarten (K) year. METHODS: A measurement-burst design was employed to examine 3 different measures of child sleep duration in 7-day bursts at pre-K (July-August), early K (late September), mid-K (late November), and late K (mid-to-late April), using wrist actigraphy. These measures included mean amounts of child sleep per 24-hour period across the full week, proportion of 24-hour periods per week that children slept 10 or more hours, and proportion of nighttime sleep periods per week that children slept 10 or more hours. Children's outcomes at early, mid-, and late K were provided by their K teachers blind to children's sleep histories, and by assessments administered by project staff. RESULTS: Among the 3 sleep measures examined, regularity of nighttime sleep in which children slept 10 or more hours per night, especially at pre-K, consistently predicted more favorable K outcomes in both socioemotional, learning engagement, and academic domains. Results suggested that establishing healthy nighttime sleep habits before K start was especially promotive of better K adjustment across the full K year. These findings were controlled for income-to-poverty threshold ratios, child health status, and number of missed school days. CONCLUSIONS: Efforts to promote a favorable transition to first-time schooling should pay particular attention to sleep hygiene and regularity of 10-plus hours of nightly child sleep established before the start of K.