When was the last time you engaged in unethical behavior? Be honest, now, and be specific: What time of day was it when you cheated on that test, lied to your spouse, or stole that item from the company break room?
If it was late afternoon or evening, you don’t have an excuse, exactly, but you certainly have company.
A newly published paper entitled The Morning Morality Effect suggests we’re more likely to act unethically later in the day. It provides further evidence that self-control is a finite resource that gradually gets depleted, and can’t be easily accessed when our reserves are low.
“Our findings suggest that mere time of day can lead to a systematic failure of good people to act morally,” write Maryam Kouchaki of Harvard University and Isaac Smith of the University of Utah. Their study is published in the journal Psychological Science.
Kouchaki and Smith suggest that organizations “need to be more vigilant about combating the unethical behavior of customers (or employees) in the afternoon.”
Kouchaki and Smith describe four experiments that provide evidence for their thesis. In the first two, participants—62 and 65 undergraduates, respectively—took part in a visual-perception test that awarded them money for correct answers. They worked on computers in unsupervised, partitioned spaces, giving them the opportunity to lie to increase their payment.
In both groups, people who performed the experiment in the afternoon “engaged in clear cheating” more frequently than those who did so in the morning.
Participants in the second experiment also completed a series of word fragments—for example, filling in letters to create a word ending in the letters RAL. Researchers were curious to see if their minds would guide them to the word “moral” or take them in a different direction entirely—say, to the word “coral.”
They found people who took part in the afternoon sessions “completed the fragments with fewer morality-related words than did those in the morning sessions.” The researchers interpret this to reflect a lowered “capacity for moral awareness” later in the day.
A third experiment featured 102 people recruited from Amazon’s Mechanical Turk. They were randomly assigned a block of time (either 8 to 11 a.m. or 3 to 6 p.m.) and instructed to perform “a decision-making task in which they had an opportunity to lie to earn more money.”
Once again, “participants in the afternoon lied more than did those in the morning,” the researchers write. The p.m. participants also reported greater levels of “cognitive fatigue.”
For the final experiment, 70 people recruited online were asked to solve a series of matrices and report their success. The more they solved, the greater their monetary payoff. Some of the matrices were unsolvable; the assertion one of them had been cracked was a clear indication of dishonesty.
Participants in the morning and afternoon groups both “cheated to some degree,” the researchers report, “but afternoon participants cheated more.”
Those who took part in this final experiment also responded to a series of statements measuring their tendency to disengage ethically. For instance, they expressed their agreement or disagreement with assertions such as, “It’s hardly a sin to inflate your own credentials.”
Interestingly, the people who responded negatively to such statements—thereby insisting on upholding strong morals—were also the ones who saw the largest decline in ethical behavior from a.m. to p.m. Apparently they had the strength to resist temptation early in the day, but gradually lost it as the hours ticked by.
For Kouchaki and Smith, this provides additional evidence that “the capacity for self-control is like a muscle, and requires rest after use for its strength to be restored.” (Perhaps watching an enjoyable television rerun would help.) As “self-regulatory resources are gradually depleted throughout the day,” they argue, “people are more likely to behave unethically in the afternoon than in the morning.”
It’s worth noting that some days are more taxing than others, and—if this theory is correct—result in a greater draw-down of one’s self-control reserve. It’d be interesting to do these same experiments after surveying participants regarding what temptations they had passed up during the course of the day.
A few practical implications arise from these findings. Kouchaki and Smith suggest that organizations “need to be more vigilant about combating the unethical behavior of customers (or employees) in the afternoon.” Indeed, that vigilance could expand to individuals, who might want to wait on major ethical choices until they’ve had a good night’s sleep.
So if you suspect you’re being swindled or lied to, check your watch. If the hour is getting late, your wariness just may be justified.