HONESTY WEAKENS IN THE AFTERNOON

If you're shopping for a used car—or deposing a witness—try to do it in the morning.

That's the implication of new research from scientists at Harvard University and the University of Utah, who found that people are quite a bit more honest in the morning than in the afternoon. (click below to read more)

In a second trial, afternoon volunteers not only cheated more on the perception task but showed lower moral awareness. Given four word fragments to complete, including "_ _ R A L" and "E_ _ _ C_ _ ," morning participants were nearly three times likelier to complete the words as "moral" and "ethical" (versus "coral" and "effects").In one experiment, volunteers assigned a simple visual perception task were given a financial incentive to cheat. Sure enough, afternoon participants cheated 20% more than did their morning counterparts.

To eliminate self-selection bias—perhaps morning people are just more ethical—and the possibility that mood played a role, the researchers tried yet another experiment, this time giving participants an incentive to lie about something. Volunteers were assigned randomly to a morning or afternoon slot and, predictably, afternoon participants lied more. Mood didn't matter.

In a fourth experiment, the scientists found that the time-of-day effect was especially strong among participants who were least prone to modifying their ethical beliefs to reduce guilt or self-flagellation.

What accounts for all this? Consistent with earlier studies of self-control, the researchers found evidence that, as the day wears on, mental fatigue sets in from hours of decision-making and self-regulation, raising the odds of transgression. "Unremarkable daily activities," the researchers write, can produce depletion that leads them "to act in ethically questionable ways."

Since so many of us are fed up with our better angels by afternoon, the findings suggest that "morally relevant tasks should be deliberately ordered throughout the day." In other words, when morality matters, the early bird catches the worm.

—"The Morning Morality Effect: The Influence of Time of Day on Unethical Behavior," Maryam Kouchaki and Isaac H. Smith, Psychological Science (Oct. 28)