Document Type: Original Articles


1 Department of Psychology, Shahid Beheshti University, Tehran, Iran

2 Assistant professor of pediatric surgery, Shahid Sadoqi University of Medical Science, Yazd, Iran


Background: The present study aimed at studying the morningness-eveningness chronotype (MEC) of daily and weekly biorhythm fluctuations in the aggression of preschool children. Methods: This was a causal-comparative study. The statistical population was preschool children in Tehran. One hundred children were selected through purposive sampling. They were examined at different times of day (08:00, 10:00, 13:00 and 15:00) and different days of the week (Saturday, Sunday, Monday, Tuesday and Wednesday). The data collection tool used was the MEC questionnaire for children, a behavioral questionnaire for preschool children and a self-report questionnaire about aggression. The data was analyzed using mixed ANOVA. Results: The results showed that the aggressive behavior of pre-school children in the educational environment varies throughout the day and week. Also, the aggressive performance of preschool children in the morning differed from that of mid-session children or evening-type children in the educational environment during the week (P<0.01). Conclusion: The results of the behavioral questionnaire showed that the effect of the group on the level of aggression was not significant, but the effect of the day of the week and time of day was significant.


  1. Martin-Storey A, Serbin LA, Stack DM, Ledingham JE, Schwartzman AE. Self and peer perceptions of childhood aggression, social withdrawal and likeability predict adult substance abuse and dependence in men and women: A 30-year prospective longitudinal study. Addictive behaviors. 2011 Dec 1;36(12):1267-74.
  2. Suter M, Pihet S, de Ridder J, Zimmermann G, Stephan P. Implicit attitudes and self-concepts towards transgression and aggression: Differences between male community and offender adolescents, and associations with psychopathic traits. Journal of adolescence. 2014 Jul 1;37(5):669-80.
  3. Street NW, McCormick MC, Austin SB, Slopen N, Habre R, Molnar BE. Sleep duration and risk of physical aggression against peers in urban youth. Sleep health. 2016 Jun 1;2(2):129-35.
  4. Burk LR, Armstrong JM, Park JH, Zahn-Waxler C, Klein MH, Essex MJ. Stability of early identified aggressive victim status in elementary school and associations with later mental health problems and functional impairments. Journal of abnormal child psychology. 2011 Feb 1;39(2):225-38.
  5. Nolen-Hoeksema S, Fredrickson B, Loftus GR, Lutz C. Introduction to psychology. Cengage Learning; 2014.
  6. Wright Jr KP, Lowry CA, LeBourgeois MK. Circadian and wakefulness-sleep modulation of cognition in humans. Frontiers in molecular neuroscience. 2012 Apr 18;5:50.
  7. Salmani F, Ahmadi faraz M, Mansour zadeh Z. The Relationship between Different Phases of Moon and Students' Emotional States. IJN. 2013; 26 (83) :39-47. [Persian].
  8. Sato T, Ida T, Kojima M. Role of biological rhythms in the performance of physical activity. The Journal of Physical Fitness and Sports Medicine. 2017 May 25;6(3):125-34.
  9. Moore-Ede MC, Sulzman FM, Fuller CA. The clocks that time us: physiology of the circadian timing system. Harvard Univ Pr; 1982.
  10. Selvi Y, Aydin A, Atli A, Boysan M, Selvi F, Besiroglu L. Chronotype differences in suicidal behavior and impulsivity among suicide attempters. Chronobiology international. 2011 Mar 1;28(2):170-5.
  11. Clark AV. Causes, Role, and Influence of Mood States. Nova Publishers; 2005.
  12. Mohammadi N, Ghamarani A, Yarmohamadian A. The Effect of circadian rhythms (morningness- eveningness) on quality of sleep and behavioral problems in primary school students. JPEN. 2016; 2 (3) :25-34. [Persian].
  13. Könen T, Dirk J, Schmiedek F. Cognitive benefits of last night's sleep: daily variations in children's sleep behavior are related to working memory fluctuations. Journal of Child Psychology and Psychiatry. 2015 Feb;56(2):171-82.
  14. Chung MH, Liu WI, Lee HL, Hsu N. Selected neurophysiological, psychological, and behavioral influences on subjective sleep quality in nurses: a structure equation model. PloS one. 2013 Nov 20;8(11):e79529.
  15. Adan A, Archer SN, Hidalgo MP, Di Milia L, Natale V, Randler C. Circadian typology: a comprehensive review. Chronobiology international. 2012 Nov 1;29(9):1153-75.
  16. Levi F, Schibler U. Circadian rhythms: mechanisms and therapeutic implications. Annu. Rev. Pharmacol. Toxicol.. 2007 Feb 10;47:593-628.
  17. Zargar Y. Construction of Iranian Addiction Potential Scale. Proceedings of the 2nd congress on Iranian Psychology Association. 2008. Tehran, Iran, P, 398-401.
  18. Ponce C, Alcorta M. De l’ecole maternelle à l’ecole primaire: fluctuations journalières de l’attention. Enfance. 2011(4):445-63.
  19. Wickersham L. Time-of-day preference for preschool-aged children. Chrestomathy: Annual Review of Undergraduate Research. 2006;5:259-68.
  20. Blatter K, Cajochen C. Circadian rhythms in cognitive performance: methodological constraints, protocols, theoretical underpinnings. Physiology & behavior. 2007 Feb 28;90(2-3):196-208.
  21. Alcorta M, Ponce C, Bonnet, J. Preschoolers daily fluctuations of attention and psycho-social adaptation. XIIth European Conference on Developmental Psychology Submission Deadline. 2004.
  22. Muro, A., Gomà-i-Freixanet, M., & Adan, A. (2012). Circadian typology and sensation seeking in adolescents. Chronobiology international, 29(10), 1376-1382.
  23. Goldstein D, Hahn CS, Hasher L, Wiprzycka UJ, Zelazo PD. Time of day, intellectual performance, and behavioral problems in morning versus evening type adolescents: Is there a synchrony effect?. Personality and individual Differences. 2007 Feb 1;42(3):431-40.
  24. Natale V, Di Milia L. Season of birth and morningness: comparison between the northern and southern hemispheres. Chronobiology international. 2011 Oct 1;28(8):727-30.
  25. Kang JI, Park CI, Sohn SY, Kim HW, Namkoong K, Kim SJ. Circadian preference and trait impulsivity, sensation-seeking and response inhibition in healthy young adults. Chronobiology international. 2015 Feb 7;32(2):235-41.
  26. Schlarb AA, Sopp R, Ambiel D, Grünwald J. Chronotype-related differences in childhood and adolescent aggression and antisocial behavior–A review of the literature. Chronobiology international. 2014 Feb 1;31(1):1-6.
  27. Vollmer C, Randler C. Circadian preferences and personality values: Morning types prefer social values, evening types prefer individual values. Personality and Individual Differences. 2012 Apr 1;52(6):738-43.
  28. Diaz-Morales JF, Escribano C. Consequences of adolescent’s evening preference on psychological functioning: a review. Anales de Psicologia/Annals of Psychology. 2014 Jan 1;30(3):1096-104.
  29. Werner H, LeBourgeois MK, Geiger A, Jenni OG. Assessment of chronotype in four-to eleven-year-old children: reliability and validity of the Children's Chronotype Questionnaire (CCTQ). Chronobiology international. 2009 Jan 1;26(5):992-1014.
  30. Carskadon MA, Vieira C, Acebo C. Association between puberty and delayed phase preference. Sleep. 1993 May 1;16(3):258-62.
  31. Shahim S. Preparation of behavioral problems questionnaire for pre-school children. Journal of Social and Human Sciences University of Shiraz. 1996; 12(1): 47-64. [Persian].
  32. Saatchi M, Kamkari K, Askarian M. Psychological tests. Tehran: Virayesh Publication. 2010; [Persian].
  33. Burg JE. The emotions thermometer: An intervention for the scaling and psychoeducation of intense emotions. Journal of family psychotherapy. 2005 Jan 4;15(4):47-56.