Parental Enforcement of Bedtime During Childhood Modulates Preference of Japanese Junior High School Students for Eveningness Chronotype

Abstract

We examined the effect of home bedtime discipline during childhood on morningness and eveningness (M-E) preference by Japanese junior high school students. M-E was assessed by the M-E Questionnaire (MEQ) of Torsvall and Akerstedt (the higher the score, the greater the preference for morningness), and parental determination of bedtime during childhood was ascertained using an original questionnaire. The average M-E score of adolescents living in urban Kochi City (mean +/- SD; 15.10 +/- 3.42) was significantly lower (P < .01) than the score of those in suburban districts (16.14 +/- 3.44). Overall, 43.1% of the junior high school students in Kochi City compared to 53.0% of the students living in suburban districts had their bedtime decided during childhood by parents (P < .01). In Kochi City, the M-E score for boys (14.62 +/- 3.51) was lower (P < .01) than girls (15.53 +/- 3.28). During childhood, parents decided the bedtime for 49% of the girls compared to 36.6% of the boys (P < .01). Boys whose bedtime was not decided by parents during childhood had a somewhat stronger preference for eveningness (14.20 +/- 3.53) (P < .05) compared to those whose bedtime was decided by parents (15.12 +/- 3.36). The results suggest bedtime discipline at home during childhood has an effect on adolescent chronotype, modulating the extent of shift to evening ness in Japanese junior high school boys in particular.

Shiftworking families: parents' working schedule and sleep patterns of adolescents attending school in two shifts

“…2 high school students 5 and Taipei junior high school students 4 have shown that parental control of sleep schedule decreases with age of adolescents, both for bedtime and wake-up time. In a study of Japanese junior high school adolescents 12 parental control of bedtime during earlier childhood was found to attenuate phase shift to eveningness in adolescent boys.…”

“…The data for actual parental control of adolescents' bedtime and wake-up time are limited and differ between countries. 2,4,5,12 A comparison of adolescents (ages 10-11, 12-13 and high school) in the USA showed that parental control of bedtime on school nights was less frequent for high school adolescents than younger groups of adolescents. 2 At the same time, control of wake-up time, either imposed by parents or by alarm clock, was more frequent in older groups of adolescents.…”

Morningness-eveningness and Fatigue in Adolescence

“…U ovom istraživanju utvrđene su značajne razlike: adolescentice su bile značajno sklonije večernjosti od adolescenata. Dobiveni nalazi najčešće se tumače ranijim početkom puberteta kod djevojčica i njihovim ranijim doživljavanjem bioloških promjena koje sudjeluju u cirkadiurnoj regulaciji (3,6,7,27). Adolescentice općenito radnim danom idu kasnije na spavanje i ustaju ranije, ali to onda nadoknađuju vikendom kada je duže spavanje više u skladu s njihovim cirkadiurnim preferencijama (26).…”

“…Najuočljivije promjene povezane sa spavanjem u adolescenciji vide se u preferenciji kasnijeg odlaska na spavanje i u razlikama u rasporedu spavanja i buđenja između radnog tjedna i vikenda (3)(4)(5)(6)(7). Ispitivanja pokazuju da samo 15 % adolescenata spava oko 8 sati tijekom radnih dana kada moraju ići u školu, a oko 26 % adolescenata izjavljuje da spava oko 6 sati ili manje, te da nedostatak spavanja nastoje kompenzirati spavajući duže vikendom (8).…”

“…The most obvious changes associated with sleeping in adolescence are seen in the preference for late bedtimes and in the differences of the sleep-wake schedule between the weekdays and weekends (3)(4)(5)(6)(7). Studies show that only 15% of adolescents sleep as long as eight and a half hours on school nights, and 26% say they usually sleep six and a half hours or less.…”