Does the timing of assessment matter? Circadian mismatch and reflective processing in university students

University students are required to engage with new content and to be assessed at specific times of the day. Research has shown that circadian rhythms differ between individuals, with impacts on optimal functioning times. We investigate the extent to which deliberate, reflective thinking (critical for university level tasks) is impacted by the timing of tasks and the interaction of task timing with circadian rhythms. We use Cognitive Reflection Test (CRT) questions to assess students’ ability to use reflective thinking. By grouping students according to their diurnal preference (morning types or evening types), we either match or mismatch the timing of the CRT assessment with diurnal preference. We find that students experiencing circadian mismatch (morning types being assessed in the evening, or evening types being assessed in the morning) perform significantly worse on the CRT, suggesting less ability to invoke reflective thinking at times of circadian mismatch. This finding suggests that timing important assessments during the day, rather than in the early morning or evening, might improve performance of mismatched students.