Chronotype in college science students is associated with behavioral choices and can fluctuate across a semester

ABSTRACT

Many students self-report that they are “night owls,” which can result from neurodevelopmental delays in the circadian timing system. However, whether an individual considers themselves to be an evening-type versus a morning-type (self-reported chronotype) may also be influenced by academic demands (e.g. class start times, course load) and behavioral habits (e.g. bedtime social media use, late caffeine consumption, daytime napping). If so, then chronotype should be malleable. We surveyed 858 undergraduate students enrolled in demanding science courses at up to three time points. The survey assessed morning/evening chronotype, global sleep quality, academics, and behavioral habits. Evening and morning-type students showed similar demographics, stress levels, and academic demands. At baseline measurements, relative to morning-types, evening-types showed significantly worse sleep quality and duration as well as 22% greater bedtime social media usage, 27% greater daytime napping duration, and 46% greater likelihood of consuming caffeine after 5pm. These behavioral habits partially mediated the effects of self-reported chronotype on sleep quality/duration, even after controlling for demographic factors. Interestingly, 54 students reported switching from being at least moderate evening-types at baseline to being at least moderate morning-types later in the semester and 56 students showed the reverse pattern (6.3% of students switched from “definitely” one chronotype to the other chronotype). Evening-to-morning “chrono-switchers” consumed less caffeine after 5pm and showed significantly better sleep quantity/quality at the later timepoint. Thus, some students may consider themselves to be night owls in part because they consume caffeine later, take more daytime naps, or use more social media at bedtime. Experimental work is needed to determine whether nudging night owls to behave like morning larks results in better sleep health or academic achievement.

KEYWORDS:

• Behavioral choices
• chronotype switching
• circadian preference
• sleep habits
• STEM learning

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are openly available in Open Science Framework at https://osf.io/k9udb/.

Supplementary data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/07420528.2023.2203251

Notes

1. The lowered response rate reflects that the chronotype was sometimes not completed due to time constraints and this item was sometimes not included in the copying of questionnaire packets.

Additional information

Funding

This study was supported by the National Science Foundation [1920730 and 1943323]. The funders had no role in data interpretation, writing, or the decision to submit the manuscript. C.G. was supported by the Alzheimer’s Association [AARFD-22-928372], the American Academy of Sleep Medicine Foundation [290-FP-22], the National Institute on Aging [RF1AG059867], and the BrightFocus Foundation [A2020886S].