Why Early Birds Can't Be Trusted Late In The Day (Sort Of)

You're more likely to lie when you're tired.

Why It's Important

It's a Friday afternoon and you've had a long and strenuous work week. Your boss stops by your cubicle and asks if you mailed the letters he left you that morning. The answer is no, but you can just mail them on Monday. He'll never know, right? You're exhausted, so you lie and say, "Yep, sure did." But you're an honest and hard-working employee, so what gives?

Both energy and ethics vary over time. In a 2013 study, researchers from Harvard University and the University of Utah discovered what they've coined the "morning morality effect." Through a series of four experiments measuring the behaviors of both undergraduate college students and adults, they concluded that most people experience "decreases in moral awareness and self-control in the afternoon." Everyday events progressively tax people throughout their day until they're 20% to 50% more likely to be dishonest. And according to Harvard University's Maryam Kouchaki, "people who usually behave more ethically were the most susceptible to the negative consequences." But do these findings ring true for both morning people and night owls? That's where circadian rhythms come into play.

Smart Graphic

Why It's Relevant

In a 2014 study, three researchers decided to qualify the claim of a "morning morality effect." Instead of a long day at work, they postulated that sleep habits could be to blame for out-of-character unethical behaviors. In the study, they gathered "larks" (morning people) and "owls" (night people) into a lab and gave them a simple problem to solve for cash prizes. Since they were told the results would be anonymous, some people lied to make more money. But who? You might've guessed it: the night owls. They ran a second, similar experiment both in the morning and at night. Each time, larks were more dishonest in the afternoon and owls lied more in the morning—both when their circadian rhythms waned. This is because circadian rhythms help process blood sugar, which improves attention, emotion regulation, impulse control, coping mechanisms, and restraint from impulsive or aggressive behavior. This knowledge is important for managers when deciding which types of assignments they should assign to each type of employee throughout the day. So, never trust a lark after 3pm. Just kidding (sort of).

Editors' Picks: Our Favorite Videos About Lying

The Time Of Day You're Most Likely To Lie & Cheat

This study began with the theory that people get worn down throughout the day. Hear the results:

Key Facts In This Video

  1. Morality lives in the right hemisphere of the brain and scientists have found a way to influence our moral compass. 00:28

  2. We are more prone to lie, cheat, and steal in the afternoon. 02:01

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Written by Curiosity Staff December 9, 2016

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