Mismatch between perceived family and individual chronotype and their association with sleep-wake patterns.

While social zeitgebers are known to shape diurnal preference, little research has been devoted to determining the contribution of the familiar group chronotype as social zeitgeber on individual circadian rhythms and sleep-wake patterns in adult subjects. The current study aimed to examine the matching between perceived family chronotype and individual chronotype and their relationship with sleep-wake patterns on weekdays and weekends, diurnal subjective somnolence, and substance consumption. Nine hundred and forty-two Colombian adults completed the Composite Scale of Morningness, the Epworth Sleepiness Scale, and responded to a questionnaire about circadian preferences of their family nucleus. We found evidence of a mismatch between perceived family and individual chronotype, mainly for morning-type individuals (Cohen's Kappa = -0.231; p < 0.001). This mismatch was associated with diurnal subjective somnolence (β = 0.073; p < 0.001) and specific sleep-wake patterns (p < 0.01). In addition, subjects with evening-type families showed higher caffeine and alcohol consumption (p < 0.001). To our knowledge, this is the first study to assess and report the mismatching between perceived family and individual chronotypes, and it adds to the existing body of knowledge regarding the influence of social zeitgebers on circadian rhythms. This is particularly relevant since mismatching between circadian physiology and environmental cues have been shown to lead to diverse pathologies.