Developmental perspectives on morningness-eveningness and social interactions

Developmental perspectives on sleep/wake rhythmicity have been neglected in research, yet evidence from chronobiological sources, infant sleep data, and adult light treatment studies suggest continuities in individual differences in internal synchronization to light-dark cycles. Developmental systems suggest maintenance through strong contextual constraints, perturbed only by unusual alterations in social demands and light exposure, such as shift work. Retrospective data from university students, employing the Morningness-Eveningness Questionnaire (MEQ), supported predicted continuity of sleep/wake patterns and associated states of alertness and fatigue as a function of time of day as well as relations with different patterns of social interactions with parents over dairy routines in childhood and adolescence. Eveningness is related to greater difficulty meeting familial and social demands for morning performance than Morningness.