Sleep and perceived control: Differences in sleep quality, free will belief, and locus of control in parents and non-parents

Beliefs about personal agency, including free will and locus of control, shape our perceptions to influence outcomes and regulate behaviour. Sleep quality influences these beliefs through its impact on attention, self-regulation, and coping capacity, with parents particularly vulnerable due to chronic caregiving demands. A community sample of 441 adults (235 parents) completed an online survey assessing free will belief, locus of control, sleep quality, and psychological distress. Multi-group SEM and t -tests examined sleep-agency relationships; poorer sleep was unexpectedly associated with higher belief in free will (β = 0.17, p = .037) and lower chance externality (β = −0.15, p = .042) among parents, with nonsignificant effects observed in non-parents. Parents reported poorer sleep ( d = 0.27), lower free will beliefs (ΔM = −0.32, p = .029), higher external control beliefs attributed to powerful others (ΔM = 0.42, p = .012) and chance (ΔM = 0.38, p = .006) than non-parents. Agency beliefs may function as compensatory mechanisms under conditions of fatigue, such as during parenting, suggesting the value of interventions that strengthen perceptions of control alongside strategies that support sleep. Enhancing agency beliefs may therefore promote resilience and wellbeing in parents by supporting compensatory perceptions of control under sleep-related fatigue.