title: Sleep quantity, quality and optimism in children.
abstract: We tested the relationship of objectively measured sleep quantity and quality with positive characteristics of the child. Sleep duration, sleep latency and sleep efficiency were measured by an actigraph for an average of seven (range = 3-14) consecutive nights in 291 8-year-old children (standard deviation = 0.3 years). Children's optimism, self-esteem and social competence were rated by parents and/or teachers. Sleep duration showed a non-linear, reverse J-shaped relationship with optimism (P = 0.02), such that children with sleep duration in the middle of the distribution scored higher in optimism compared with children who slept relatively little. Shorter sleep latency was related to higher optimism (P = 0.01). The associations remained when adjusting for child's age, sex, body mass index, and parental level of education and optimism. In conclusion, sufficient sleep quantity and good sleep quality are related to children's positive characteristics. Our findings may inform why sleep quantity and quality and positive characteristics are associated with wellbeing in children.
authors.affiliation: Department of Psychology, University of Helsinki, Helsinki, Finland.
authors.forename: Sakari
authors.initials: S
authors.lastname: Lemola
authors.forename: Katri
authors.initials: K
authors.lastname: Räikkönen
authors.forename: Michael F
authors.initials: MF
authors.lastname: Scheier
authors.forename: Karen A
authors.initials: KA
authors.lastname: Matthews
authors.forename: Anu-Katriina
authors.initials: AK
authors.lastname: Pesonen
authors.forename: Kati
authors.initials: K
authors.lastname: Heinonen
authors.forename: Jari
authors.initials: J
authors.lastname: Lahti
authors.forename: Niina
authors.initials: N
authors.lastname: Komsi
authors.forename: Juulia E
authors.initials: JE
authors.lastname: Paavonen
authors.forename: Eero
authors.initials: E
authors.lastname: Kajantie
mesh_terms: D056044:Actigraphy; D000367:Age Factors; D002648:Child; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D010290:Parents / Q000523:psychology; D010551:Personality / Q000502:physiology*; D012649:Self Concept; D012737:Sex Factors; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000523:psychology; D012917:Social Adjustment