Another reason to get a good night’s rest: fatigue makes you more likely to cheat

Night owls shouldn't be making key decisions early in the morning

Fatigued-looking office worker fudging a chart

(Kagan McLeod)

Whether you tell a lie today could depend on how well you slept last night, according to new research from John Hopkins University, the University of Washington and Georgetown University. Researchers found that the energy we need to exert self-control fluctuates, and unethical behaviour, like cheating and lying, depends on both our natural circadian rhythms and the time of day.

The study’s authors conducted two experiments. The first focused on behaviour in the morning and had participants report the number of tasks they completed – the more tasks completed, the more money they would receive. Participants believed that their work was anonymous and so they could potentially over report the number of tasks they finished to earn more money. But researchers were able to check how many they actually solved and see who cheated by over-reporting.

In the second experiment, the researchers tested whether unethical behaviour depended on both circadian rhythms and the time of day. They assigned participants to sessions either early in the morning (7 to 8:30 a.m.) or late at night (midnight to 1:30 a.m.), and told them to roll a die. Participants reported the number that appeared – the higher the number, the more money they were paid. Although, the study’s authors didn’t know the numbers that were rolled, they knew that everyone should report an average of 3.5, so any differences across conditions like morning people in the morning versus evening people in the morning, would indicate cheating.

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Based on the two experiments, researchers said in a summary published in the Harvard Business Review that people who consider themselves to be “early birds” were more likely to over report their progress on a series of tasks later in the day, and self-professed night owls were more likely to cheat in the morning.

What does this mean for organizations? You and your employees might be more likely to act unethically when making a decision out of sync from your 24-hour clock, so you should try to keep chronotypes (early birds, night owls, or in between) in mind when deciding how to structure work. If you’re in charge of your own work schedule, remember that squeezing in an extra hour of work either at night (early birds) or in the morning (night owls) can create instances where resisting temptation may be harder than ever. Key take-away: When your body says it’s time for a nap, it’s not lying.

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