The early bird catches the worm: Assessing implicit theories on circadian processes at work.

Employees differ in their circadian preferences, which dictate the timing of activity and sleep during the day. Despite their relevance for daily fluctuations in energy and performance, research and practice indicate prevalent biases and misconceptions regarding circadian processes at work. Individuals seem to believe in the malleability of these circadian preferences, that earlier circadian preferences are associated with being an ideal worker, and that the morning is universally the best time for work. To systematically investigate this phenomenon, we introduce the concept of implicit theories on circadian processes at work (ITCP) to the literature and developed scales assessing three facets of ITCP: (a) the malleability facet, (b) the ideal worker facet, and (c) the time-of-day facet. Starting with construct and item development, we collected qualitative data from 141 employees (Study 1a) and quantitative data from 22 researchers (Study 1b). Next, we surveyed 1,249 participants (Studies 2-5) to establish the three-factor structure and excellent psychometric properties of the ITCP scales in both German and English. Additionally, we identified a range of personal predispositions associated with higher levels of ITCP (e.g., chronotype and workaholism) and, in turn, demonstrated that higher levels of ITCP are partly related to unfavorable individual outcomes. The findings particularly emphasize the undesirability of the ITCP ideal worker (for well-being and work-related outcomes) and the ITCP time-of-day (for sleep-related outcomes) facets. In conclusion, we hope to inspire research on circadian processes at work to finally reduce the lingering implicit theories surrounding these processes. (PsycInfo Database Record (c) 2025 APA, all rights reserved).