Prior research has consistently shown that general sleep problems such as shorter sleep duration, lower sleep efficiency, and more frequent nighttime awakenings are associated with greater disruptive behavior (DB) in children, including rule breaking, noncompliance, aggression, temper loss, and low concern for others. However, most studies have relied on parent-reported or broad sleep metrics rather than examining specific features of sleep. Very few studies have examined slow wave sleep (SWS) directly and its link to disruptive behavior, and none specifically have investigated preschool-aged children. Participant data from a larger longitudinal study investigating early childhood memory and sleep in preschoolers will be used to assess DB (via MAP-DB), general sleep quality (via actigraphy watches) and sleep macrostructure (% SWS via PSG). Analyses will include Pearson correlations between DB and sleep continuity, sleep duration, and %SWS sleep respectively, as well as regression models to predict DB from sleep continuity and duration, and to test whether adding %SWS explains additional variance in DB (ΔR²) after accounting for general sleep health. I predict a strong association amongst SWS and DB which could suggest DB is not just about child tiredness resulting from poor sleep generally, but more specifically a result of disrupted sleep macrostructure resulting in neural disadvantage for sleep benefits like plasticity and waste clearance. Better understanding of how different aspects of sleep relate to early childhood disruptive behavior can help us better determine possible intervention targets.