Simon S Smith,1 Shannon L Edmed,1 Sally L Staton,1 Cassandra L Pattinson,2 Karen J Thorpe11Institute for Social Science Research (ISSR), The University of Queensland, Brisbane, QLD, Australia; 2Brain Tissue and Injury Branch, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USAPurpose: Major changes in the timing, duration, and function of sleep occur during childhood. These changes include the transition from habitual napping to infrequent napping. This transition is likely to reflect, at least in part, neurocognitive development. This study sought to identify factors that discriminate between four groups of children with different teacher-reported responses to naptime in childcare: those who nap (nappers), sometimes nap (transitioners), do not nap (resters), and neither nap, nor lie still (problem nappers).Methods: Standardized observations of sleep and sleep behaviors, daytime behaviors across a number of domains, and direct neurocognitive assessment of 158 preschool aged children (aged 49–72 months; 54% male) attending childcare centers in Queensland (QLD), Australia, were adopted as part of a large longitudinal study of early childhood, the Effective Early Education Experiences (E4Kids) study. Discriminant function analysis was used to examine how age, parent education, nighttime sleep duration, cognitive functioning, behavior problems, and temperament differentiated the four groups.Results: Three discriminant functions were identified and defined as maturation (strong loadings of nighttime sleep duration, cognitive function, and age), socioeconomic status (parental education), and behavioral problems (externalizing behavior, temperament, and internalizing behavior). These functions accounted for 62.9%, 32.6%, and 4.5% of the between-groups variance, respectively. Children defined as nappers (n=44) had significantly shorter duration of nighttime sleep, were younger, and had lower cognitive functioning scores than did other groups. Problem nappers, (n=25) were more likely to have parents with lower levels of education than did transitioners (n=41). Standard behavior and temperament measures did not significantly differentiate the groups.Conclusion: The findings support an interaction between cognitive development, sleep behaviors, and the individual needs and circumstances of children. Further research in this area could make a strong contribution to theory and practice in early childhood education, and a strong contribution to understanding of children’s development.Keywords: napping, children’s sleep, sleep behavior, early childhoo