title: Timing of examinations affects school performance differently in early and late chronotypes.
abstract: Circadian clocks of adolescents typically run late-including sleep times-yet adolescents generally are expected at school early in the morning. Due to this mismatch between internal (circadian) and external (social) times, adolescents suffer from chronic sleep deficiency, which, in turn, affects academic performance negatively. This constellation affects students' future career prospects. Our study correlates chronotype and examination performance. In total, 4734 grades were collected from 741 Dutch high school students (ages 11-18 years) who had completed the Munich ChronoType Questionnaire to estimate their internal time. Overall, the lowest grades were obtained by students who were very late chronotypes (MSFsc > 5.31 h) or slept very short on schooldays (SDw < 7.03 h). The effect of chronotype on examination performance depended on the time of day that examinations were taken. Opposed to late types, early chronotypes obtained significantly higher grades during the early (0815-0945 h) and late (1000-1215 h) morning. This group difference in grades disappeared in the early afternoon (1245-1500 h). Late types also obtained lower grades than early types when tested at the same internal time (hours after MSFsc), which may reflect general attention and learning disadvantages of late chronotypes during the early morning. Our results support delaying high school starting times as well as scheduling examinations in the early afternoon to avoid discrimination of late chronotypes and to give all high school students equal academic opportunities.
authors.affiliation: Chronobiology unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands.
authors.forename: Vincent
authors.initials: V
authors.lastname: van der Vinne
authors.affiliation: Chronobiology unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands.
authors.forename: Giulia
authors.initials: G
authors.lastname: Zerbini
authors.affiliation: High school De Nieuwe Veste, Coevorden, the Netherlands.
authors.forename: Anne
authors.initials: A
authors.lastname: Siersema
authors.affiliation: High school De Nieuwe Veste, Coevorden, the Netherlands.
authors.forename: Amy
authors.initials: A
authors.lastname: Pieper
authors.affiliation: Chronobiology unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands Institute of Medical Psychology, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: Martha
authors.initials: M
authors.lastname: Merrow
authors.affiliation: Chronobiology unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands.
authors.forename: Roelof A
authors.initials: RA
authors.lastname: Hut
authors.affiliation: Institute of Medical Psychology, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: Till
authors.initials: T
authors.lastname: Roenneberg
authors.affiliation: Chronobiology unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands Institute for Occupational, Social and Environmental Medicine, Ludwig-Maximilians-Universität München, Munich, Germany thomas@kantermann.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kantermann
mesh_terms: D000293:Adolescent; D001288:Attention / Q000502:physiology*; D002648:Child; D002940:Circadian Rhythm; D004521:Educational Measurement; D005260:Female; D006801:Humans; D008297:Male; D009426:Netherlands; D012890:Sleep / Q000502:physiology*; D013334:Students / Q000523:psychology; D011795:Surveys and Questionnaires; D013997:Time Factors; D014940:Work Schedule Tolerance / Q000523:psychology*
keywords: chronotype; examinations; grades; school performance; sleep deficiency; sleep timing; time of day