Abstract
Path analysis was used to examine the relationship between class start times, sleep, circadian preference, and academic performance in college-aged adults. Consistent with observations in middle and high school students, college students with later class start times slept longer, experienced less daytime sleepiness, and were less likely to miss class. Chronotype was an important moderator of sleep schedules and daytime functioning; those with morning preference went to bed and woke up earlier and functioned better throughout the day. The benefits of taking later classes did not extend to academic performance, however; grades were somewhat lower in students with predominantly late class schedules. Furthermore, students taking later classes were at greater risk for increased alcohol consumption, and among all the factors affecting academic performance, alcohol misuse exerted the strongest effect. Thus, these results indicate that later class start times in college, while allowing for more sleep, also increase the likelihood of alcohol misuse, ultimately impeding academic success. (Author correspondence: [email protected])
Notes
1 There is evidence of a suppression effect between bedtime and sleep duration. While the direct effect of bedtime on sleep duration is negative, i.e., later bedtimes tend to result in less total sleep, the indirect effect—via rise times—is positive. That is, later bedtimes may also lead to later rise times, which are associated with more sleep overall. The former outcome is more likely on weekdays or days that have early morning activities, the latter on weekends or days when no early morning activities are scheduled.