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How Time of Day Can Affect Morality

honestyFor some people, morality appears to be a flexible concept. They might be good, honest, and upstanding in one moment and a liar and a cheat in another. Believe it or not, this sort of behavior might be a bit more common than you think. Someone’s shifting morals might have less to do with him or her as a person and more to do with the time of day.

Three Harvard Business School professors — Christopher M. Barnes, Brian Gunia, and Sunita Sah — published research in the Harvard Business Review showing a connection between a person’s chronotype (the time of day that person works most effectively) and their adherence to ethical behavior. The researchers conducted two different studies and concluded that “morning people,” or “larks,” are more likely to behave unethically at night and “evening people,” or “night owls,” are more likely to behave unethically in the morning.

The first experiment tested participants’ behavior in the morning. The participants were asked to solve as many matrices as possible. Then, they were instructed to tell the researchers how many matrices they had solved and would be rewarded for each correct answer. Participants were told that their work was anonymous and could therefore overreport to make more money. However, the researchers were able to check the participants’ work and found that night owls were more likely to cheat.

The second experiment tested participants’ behavior both in the early morning and late at night. Participants were told to roll a pair of dice and report their average score back to the researchers. Higher scores would result in greater monetary rewards. The researchers did not actually verify which numbers the participants rolled, but they knew that the average score should be around 3.5. Not surprisingly, the participants’ self-reported results differed based on how well their chronotype matched the time of day. During the morning experiment, larks reported an average score of 3.86 and night owls reported an average score of 4.23. During the evening experiment, larks reported an average score of 4.55 and night owls reported an average score of 3.8.

So why would someone’s circadian rhythm change their behavior? People’s energy levels change with their circadian rhythms, meaning that larks have less energy later in the day while night owls have less energy earlier in the morning. The researchers hypothesized that people who are mismatched with their circadian rhythm are more likely to behave unethically because they don’t have the energy to resist temptations.

The important takeaway from this study is that people ought to be aware of their own circadian rhythm and to keep it in mind when performing certain tasks. Employees should try to adjust their work schedule to fit their circadian rhythm if possible. Both morning larks and night owls should be aware of how they plan their day and leave important decision-making tasks for when they are most energized.

Honesty Image available from Shutterstock.

How Time of Day Can Affect Morality

Patrick Dunne

Patrick W. Dunne graduated from Chaminade University, where he studied Business and Psychology. He is currently a freelance writer whose work has appeared in Listverse, Psych Central, and other sites. You can contact him through LinkedIn and Twitter @patrickwdunne.

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APA Reference
Dunne, P. (2018). How Time of Day Can Affect Morality. Psych Central. Retrieved on November 30, 2020, from
Scientifically Reviewed
Last updated: 8 Jul 2018 (Originally: 1 Apr 2016)
Last reviewed: By a member of our scientific advisory board on 8 Jul 2018
Published on Psych All rights reserved.