Feeling better or not: Adjusting affective style moderates the association between sleep duration and positive affect on next day.

Affect is intertwined with sleep, yet how to adjust sleep duration to enhance affect remains unknown. Previous studies found that adjusting affective style, reflecting interindividual differences in emotion regulation, functions in processes where sleep modulates our affective state. Hence, this study examined whether and how it moderates the association between daily sleep duration and subsequent affect. An ambulatory assessment design was employed among 64 participants, wherein both within-person sleep duration and affect, and between-person affective styles were measured. Multilevel moderation analysis and simple-slope analysis were applied to test the moderation of adjusting affective style in the sleep-affect association. This study found that adjusting affective style significantly moderated the association between sleep duration and subsequent positive affect. Specifically, the association between sleep duration and subsequent positive affect was positive under higher adjusting affective style and negative under extremely lower adjusting affective style. However, such moderation was not observed in associations between subsequent negative affect and sleep duration. This study uncovers the relationship between sleep duration and subsequent affect, wherein the likelihood for individuals to reach more positive affective state by increasing sleeping duration might count on their ability of emotion regulation. Additionally, negative affect cannot be downregulated simply through long sleep duration.