Do people rely more on habits when sleepy? An ecological momentary assessment study.

When self-regulatory resources are depleted, people tend to act more on "autopilot", with minimal forethought. It follows that when sleepy, people should be more likely to act habitually, based on learned cue-behaviour associations that trigger behaviour automatically when the cue is encountered. This ecological momentary assessment study investigated whether, over the course of a week, between-person differences and momentary within-person variation in daytime sleepiness were associated with the reported habit strength of behaviours. Participants (N = 105, 71% female, M age = 35 years) completed a baseline assessment of sleep quality and, six times daily over 7 days, momentary assessments in which they reported the habit strength of the behaviour they were doing when prompted and their momentary sleepiness. Multilevel modelling revealed that people who were more sleepy than others were not more or less likely to act habitually, but on occasions when people were more sleepy than was typical for them, the behaviour they were engaging in tended to be more habitual (Pseudo-R