Gender differences in morning and evening lateness

Abstract

Studies of morning–evening preference consistently recognize age differences, but gender differences are rarely reported. To examine these differences, we applied the Sleep–Wake Pattern Assessment Questionnaire (Putilov 1990, 2000, 2007). Unlike unidimensional morningness–eveningness scales, it includes separate scales for the measurement of Evening and Morning lateness (E and M, respectively). Data on 7465 adolescents and adults suggest that both E and M scores significantly decline with age. Genders are identical on the sum of E and M scores, but female respondents of any age cohort have a lower E score and a higher M score. Differences between these scores remain constant across ages. Analysis of a subset of data on 2016 adults revealed significant correlation of this difference with self-reported sleep length which, however, is not significantly longer in women. We concluded that, compared to men, women prefer earlier bedtimes and later wake up times and can desire but not obtain more sleep.

Keywords:

• morningness–eveningness
• chronotype
• sleep debt
• sleep duration
• gender difference
• age trend

Acknowledgements

This study was supported by Foundation, Grant # 06-06-00263a from the Russian Foundation for Basic Research and by the Alaska-Siberia Medical Exchange Program. We appreciate very much the valuable help of Dr. John M. Booker in planning and conducting the questionnaire study of seasonal depression and the assistance of Dr. Konstantin Danilenko, Marina Kravchenko, Dmitriy Zolotarev, Dr. Vladislav Palchikov, Mike Onischenko, Natasha Buryak, Xenia Ontcheretnaya and Dr. Roman Budkevich in collecting questionnaire data.