A songbird at midday may have more chance of getting the worm — if that is a successful oral exam or job interview — than the early bird, an Italian study published on Thursday suggests.
Students had the best chance of passing oral exams around lunchtime, ranking lowest at the beginning or end of the day, the data showed.
Professor Carmelo Mario Vicario, director of the Social-Cognitive Neuroscience Lab at the University of Musina and lead author of the paper said they found: “Academic assessment outcomes vary systematically across the day, with a clear peak in passing rates around midday. Students were more likely to pass in late morning compared to early morning or late afternoon.”
Students in Italy must pass oral exams, lasting 10 to 30 minutes, that are structured like interviews. Vicario said: “We believe this pattern could extend to job interviews or any evaluative process scheduled throughout the day.”
University of Cape Town sleep scientist Prof Dale Rae said of the findings: “The students being examined between 11am and 1pm may have had a double advantage — more sleep opportunity the night before the exam and being tested at a time when cognitive performance may peak [about midmorning to before lunch].”
In adolescence, people’s body clocks (or chronotypes) shift later so they are more evening-orientated and early exams are not ideal for most students.
“For late adolescents, in addition to this later shift in their chronotype, they also experience less sleep pressure at night, which means earlier bedtimes are harder to achieve, so they are typically under-slept on days when they have to wake up early,” she said.
The students being examined between 11am and 1pm may have had a double advantage.
— Prof Dale Rae, UCT sleep scientist
“Chronotypes are sure to be at play, but ... it is good to remember that chronotypes exist along a spectrum — from the extreme night owl on one end to the extreme morning lark on the other,” she said, noting it was not a given that professors were more likely to be morning larks.
The Italian team was motivated to investigate the influence of times on exam results by research that found judges were more likely to favour defendants after meal breaks, or at the beginning of a session.
“However, this could have been influenced by different types of case being presented at different times. So the researchers looked at oral exams, which are more subjective than legal decisions. If the time of day influences people’s judgment, large-scale data on exam outcomes should show evidence of it,” the team noted.
They analysed the University of Musina database of exam results conducted between October 2018 and February 2020 — collecting the time, date and outcome of 104,552 assessments delivered by 680 examiners for 1,243 courses. The results were published in the peer-reviewed journal Frontiers of Psychology on Thursday.
Vicario said of the Italian oral exams: “There's no standardised format: professors ask questions based on the course content, and grades are assigned on the spot. These exams can be highly stressful due to their unpredictable nature and the strong weight they carry in academic progression.”
To conduct statistical analysis based on the time the exam began, the researchers factored in the difficulty of individual exams by assessing the number of credits granted towards a degree per exam.
Only 57% of exams were passed. The peak of the bell curve for passing was at noon and there was no significant difference in the chance of passing if students had the exam at 11am or 1pm. Early mornings (8am or 9am) and late afternoons (3pm and 4pm) had similar outcomes.
“These findings have wide-ranging implications. They highlight how biological rhythms — often overlooked in decision-making contexts — can subtly but significantly shape the outcome of high-stakes evaluations,” said co-author Prof Alessio Avenanti of the University of Bologna.
Prior research has shown that cognitive performance improves during the morning, declining in the afternoon, the researchers said.
In the late afternoon, the researchers noted that declining energy levels and focus among students could compromise their performance while their examiners “might be experiencing decision fatigue, leading them to mark more harshly”.
Vicario suggested: “Students might benefit from strategies like ensuring quality sleep, avoiding scheduling important exams during personal ‘low’ periods, and taking mental breaks before performance tasks to counteract time-of-day effects, students.
“We would be very interested in investigating whether hiring decisions, too, fluctuate in fairness or outcome depending on time of day.”
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