Analyzing the Affective Consequences of Normal Sleep Fluctuations: A Multiverse Investigation using Experience Sampling Data

How much we sleep at night is believed to impact next-day affective experiences. Yet, the existing research is encumbered by methodological limitations. To address this issue we harnessed experience sampling data (68,232 observations across 10,905 days) from 1,415 Belgian participants to examine whether normal variations in sleep duration linearly or nonlinearly influence next-day fatigue, stress, happiness, anxiety, despondence, and calmness. We also tested whether people that sleep less on average benefit more from a standard sleep increase than people that generally sleep more. We tested 10,080 models as part of a multiverse analyses in this non-pre-registered study. Findings indicate even small increases in sleep duration promote (albeit, in a small way) more positive affective experiences, that effects are generally stronger in the period after waking relative to later in the day, and that effect magnitudes differ markedly across affective experiences. Findings also tentatively indicate that the impact of sleep on fatigue and feelings of despondence soon after waking may be greater for people that sleep less on average. However, little support was gained for sleep effects being nonlinear. In short, our findings advance understanding of whether and to what extent sleep impacts various affective experiences, and reveal a range of important nuances to this relationship.