As the day wears on, we tend to get weary. Now a study finds that as a result we may be more likely to cheat or lie in the afternoon than in the morning. But only if we’re usually ethical to begin with.

Scientists showed volunteers patterns of dots on a computer and asked them to tell which side of the screen contained more dots, the right or left. Here's the kicker: the researchers gave the subjects a higher reward if they selected the right side, even if it was incorrect. And with this incentive, subjects were more likely to cheat in the afternoon than in the morning.

In another experiment the scientists showed the subjects fragments of words, and asked them to complete the word. For example, they might see the last three letters, R, A, L, of a five-letter word. And surprisingly in the morning the participants tended come up with the word "moral" whereas in the afternoon the word of choice was “coral.”

The researchers also found that people who tend to cheat regularly were just as likely to do so in the morning as in the afternoon. It was the more ethical folks who suffered lapses as the day wore on. So the early bird gets the worm…and the truth.

—Christie Nicholson

[The above text is a transcript of this podcast.]