Alarm Clock on bed (Alarm Clock on bed)

Morals are for the morning: You're more likely to cheat and lie as the day wears on, finds new research from Harvard University.

In one experiment involving computer tasks, people fudged their answers in exchange for cash 44 percent more in the afternoon than in the A.M. Another test showed people were 22 percent more likely to fib after midday.

What gives? There's evidence that shows your supply of self-control is limited, says study coauthor Maryam Kouchaki, Ph.D. “Normal activities during the day are enough to deplete self-control and increase dishonest behavior,” she says. Fatigue and hunger seem to speed this moral descent. (If you’ve been harboring a secret, it could be hurting your brain power, your health, and your happiness. Find out How Lying Affects Your Health.)

Find out How Lying Affects Your Health

Fortunately, a nap or a meal are enough to recharge your ethical batteries, Kouchaki's research suggests. Need a quicker fix? Chomping or swishing a sugary snack like gum or Gatorade excites the parts of your brain responsible for willpower, and so can boost your self-control. Spending time with people you like—even the fictional kind on TV—can also strengthen your flagging willpower, found a 2012 study from the University of Buffalo.

(Men tell an average of three lies a day. Discover your 5 biggest fibs, and how to fix each one.)

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