Social jetlag - the misalignment between a person’s body clock and the environment where they live and work - can have a negative impact on academic performance, especially in students who would naturally wake up later than their schedules allow, according to a study in Scientific Reports.

Social jetlag is becoming more common and has been tied to increased disease risks, as well as learning and attention deficits, especially in late risers. However, there has been no way to assess the impact of social jetlag on learning outcomes of large groups of people, or identify which individuals may be most affected.

Benjamin Smarr and Aaron Schirmer used two years of login data from a university learning management system to generate personal daily activity profiles for 14,894 students. They show that only 40.4% of students seemed to have body clocks that were naturally synchronized with their academic schedules, whereas about 49.2% advance and 10.4% delay their activity on class days (when activity started earlier) compared to non-class days. As a result of these delays and advances, 60% of students experienced an every-day social jet lag of at least 30 minutes. This effect was associated with decreased academic performance in students who either advanced and delayed their activity on non-class days, with the latter being the most affected.