A self-regulatory approach to the relationship between sleep and psychological strain: Integrating resource replenishment and resource enhancement

This project explored the psychological benefits of sleep in terms of an integrated self-regulatory strength model, which includes resource enhancement in addition to resource replenishment. Though sufficient sleep duration may have restorative effects on self-regulatory functioning, prolonged consistent sleep practices may also help build self-regulatory capacity via exercising self-control. Thus, sleep may have psychological implications for the stress process because of its effect on self-regulatory functioning. Using a cross-sectional survey approach, Study 1 tested and replicated a theoretical model linking individual differences (e.g., self-control and morningness), sleep habits, and psychological strain in 327 professional workers and 403 undergraduate students. Although the negative effects of poor sleep habits on strain were mediated by stable individual differences, sleep inconsistency also independently predicted strain via an interaction with sleep sufficiency in both samples. Consistent sleep practices were only associated with less strain among individuals obtaining a sufficient amount of sleep. Study 2 further explored the sufficiency by consistency interaction in a longitudinal study with 87 undergraduate students. The sufficiency-consistency interaction also predicted changes in strain and self-regulatory performance over the course of five days. Specifically, only individuals who consistently obtained a sufficient amount of sleep experienced a decrease in strain and increase in self-regulatory performance. Continued explorations into the potential resource enhancement aspect of consistent sleep may be a fruitful avenue of stress management research. Much like other routine activities that have shown to increase self-regulatory strength, consistent sleep may serve as an effective strain intervention, thereby preventing negative health effects. Practical implications of the proposed model and directions for future research are discussed.