0197 Chronotype is Influenced by Behavioral Choices and Can Fluctuate Across the Semester in STEM Students

Abstract

Abstract Introduction A delay in endogenous biological rhythms is assumed to cause undergraduate students to be “night owls,” but neurodevelopmental effects may only partially explain chronotype (circadian preference). Instead, perceived chronotype in students may result from poor sleep hygiene practices including bedtime social media use, afternoon caffeine consumption, and daytime napping. If so, then chronotype should be malleable in students to the extent that behavioral choices change. Methods We surveyed 1,120 undergraduate students who were enrolled in STEM courses across up to 3 time points during the semester. The survey assessed perceived chronotype (morning/evening type), global sleep quality, and daily habits that impact alertness and sleep hygiene (e.g., social media usage and timing, caffeine consumption and timing, and napping behavior). Results Relative to Morning Types, students who perceived themselves as being Evening Types showed 23.1% greater bedtime social media usage (t=3.14, p=.002), 35.1% greater daytime napping duration (t=4.44, p<.001), and a 44 minute later average time of caffeine consumption (even though total caffeine consumption was reduced; t=2.30, p=.022). Evening Types also reported lower subjective health (t=3.55, p<.001), with 14.2% of the association between chronotype and subjective health being mediated by bedtime social media use (direct effect: b=0.050, p=.002; indirect effect: b=0.009, p<.05). Ninety-one students reported switching from being Evening Types at baseline to Morning Types at a later survey; those who switched to Morning Types used less social media and consumed less caffeine after 5pm and they showed significant improvements across the semester in sleep duration, sleep quality, and exam scores (ps<.05). Conclusion Perceived chronotype is related to social media and caffeine consumption behaviors and is modifiable. Students who perceive themselves as night owls may find better health and academic success if they behave like morning larks. Support National Science Foundation (DRL 1920730)