Arcady A Putilov, Dmitry S Sveshnikov, Zarina V Bakaeva, Elena B Yakunina, Olga V Mankaeva, Vladimir I Torshin, Elena A Trutneva, Michael M Lapkin, Zhanna N Lopatskaya, Roman O Budkevich, Elena V Budkevich, Dmitry E Shumov, Anton I Taranov, Olga N Tkachenko, Eugenia O Gandina, Alexander E Manaenkov, Evgeniy A Cheremushkin, Natalya V Ligun, Alexandra N Puchkova, Vladimir B Dorokhov
Women and evening (late) chronotypes more often than men and morning (early) chronotypes report problems with health, mood, and sleep. Can we expect that, in turn, women report evening preference more often than men? Instead, the literature on chronotypes suggests that men report a slightly larger evening preference than women. To explain this paradoxical finding, we investigated the role of morning and evening components of earliness-lateness. Previous studies have shown that preferences for earliness-lateness (i.e. morningness-eveningness) can vary depending on whether the morning or evening hours are considered. Therefore, we tested the following hypotheses: 1. Sex is unrelated to the combination of lateness in the morning hours with lateness in the evening hours because women more often than men combine morning lateness with evening earliness rather than with evening lateness. 2. Only morning lateness is associated with sleep, mood, and health problems, while evening lateness is not. Paired assessments of morning and evening earliness-lateness and problems with health, mood, and sleep were reported by 439 male and 1143 female university students. We examined relationships between these problems, sex, morning lateness, evening lateness, and their combination. Results supported the study hypotheses. Evening lateness did not contribute to the link of combination of morning and evening lateness to health, mood, and sleep problems and 2) this combination was unrelated to sex of students. Namely, female students less often than male students reported evening lateness that did not contribute to the association of combination of morning and evening lateness with health, mood, and sleep problems. Instead, they more often reported morning lateness that was also associated with health, mood, and sleep problems. As a result, they more often reported problems with health, mood, and sleep, while sex of students was not related to combination of morning lateness with evening lateness (i.e. with morning-evening preference).