Positive psychological traits predict and facilitate good sleep quality and quantity

Sleep is essential to the maintenance of good health and wellbeing; however, surprisingly little is known about the positive antecedents of this crucial health-related behaviour. By adopting a positive psychological approach to sleep, this thesis aims to consolidate, integrate and extend the current literature by determining the collective and relative contributions of four positive psychological traits (mindfulness, self-compassion, gratitude and optimism) to overall sleep quality and quantity, cross-sectionally and prospectively. Within both cross-sectional and prospective studies, this thesis also explores the role of emotion regulation as a potential common mediator of the relationships between each of the aforementioned positive traits and sleep, in an attempt to determine whether these relationships can be situated within a broader, common framework. Based on the finding that optimism consistently emerged as a significant linear predictor of sleep in its own right, this thesis lastly presents the results of an experimental study that explored whether a brief optimism intervention might improve overall sleep quality and quantity within a student sample. Taken together, findings not only highlight the importance of considering positive traits when it comes to explaining variation in sleep outcomes and facilitating future sleep quality and quantity, but also provide interesting implications for theory and echo recent calls for new and integrative positive psychological approaches to sleep medicine.