Do tired minds have tired ideas? In two studies, we explored the role of insomnia and personality in divergent thinking, everyday creative behavior, and creative achievement. Using a well-validated measure of insomnia-the Bergen Insomnia Scale-the present work explored the differential effects of nighttime and daytime insomnia symptoms. Structural equation models found a moderate effect of a global insomnia factor on divergent thinking (β= .19). Further analysis showed time-of-day effects: nighttime sleep disturbances positively predicted divergent thinking more strongly (β= .15) than daytime disturbances (β= .03). A similar pattern emerged regarding everyday creative behavior: nighttime impairments showed a positive effect (β= .15) and daytime impairments showed a negative effect (β= -.15). Global insomnia and the time-of-day variables had small and negative effects on creative achievement. The present research highlights the importance of taking a nuanced approach to the study of insomnia and creativity.
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