'Night owls' taking morning classes get lower grades: study

Children who are "night owls" and attend early morning classes are more likely to receive lower grades, a study has found.

Students whose circadian rhythms were out of sync with their class schedules received lower grades due to 'social jet lag,' a condition in which peak alertness times are at odds with work, school or other demands.

In addition to learning deficits, social jet lag has been tied to obesity and excessive alcohol and tobacco use.

"We found that the majority of students were being jet-lagged by their class times, which correlated very strongly with decreased academic performance," said Benjamin Smarr from University of California, Berkeley in the US.

Researchers tracked the personal daily online activity profiles of nearly 15,000 college students as they logged into campus servers.

After sorting the students into "night owls," "daytime finches" and "morning larks" - based on their activities on days they were not in class - the researchers compared their class times to their academic outcomes.

"Our research indicates that if a student can structure a consistent schedule in which class days resemble non-class days, they are more likely to achieve academic success," the researchers said.

While students of all categories suffered from class-induced jet lag, the study found that night owls were especially vulnerable, many appearing so chronically jet-lagged that they were unable to perform optimally at any time of day.

"Because owls are later and classes tend to be earlier, this mismatch hits owls the hardest, but we see larks and finches taking later classes and also suffering from the mismatch," Smarr said.

"Different people really do have biologically diverse timing, so there isn't a one-time-fits-all solution for education," he said.

For the study, published in the journal Scientific Reports, the researchers analysed the online activity of 14,894 college students.

To separate the owls from the larks from the finches, and gain a more accurate alertness profile, the researchers tracked students' activity levels on days that they did not attend a class.

Next, they looked at how larks, finches and owls had scheduled their classes during four semesters from 2014 to 2016 and found that about 40 per cent were mostly biologically in sync with their class times. As a result, they performed better in class and enjoyed higher GPAs.

However, 50 per cent of the students were taking classes before they were fully alert, and another 10 per cent had already peaked by the time their classes started.