KBOI Experiment: Do people lie more in the afternoon?

BOISE, Idaho (KBOI) -- You may want to ask the questions you want answered truthfully in the morning, according to a new study done by a professor on morality and ethics at the University of Utah and a PH-D grad.

The theory called, "Morning Morality Effect," finds that people are more likely to lie in the afternoon because they are more groggy and less alert, causing them to have less self-control and tell the truth without realizing it.

The study includes several experiments to prove the theory. One of them included a group of people looking at a screen cut in half, who were asked to pick the side that had more dots. But to get the group to lie, if the participants picked one side of the screen, they got more money than if they picked the other side of the screen. The experiment concluded that more people picked the side of the screen that would get them more money more often in the afternoon.

KBOI decided to test out that study and a Boise State University lecturer, Christine Moore, offered her students as the participants. She even offered to give them an incentive: extra credit.

One group of Moore's students volunteered to meet in the morning, and another group in the afternoon. In both groups, the students were asked to pick the side of the screen with the most dots. But if they picked the right side of the screen, they got more extra credit than if they picked the left side of the screen.

There were 100 slides, but the catch was that in almost every slide, there was the same amount of dots on both sides of the screen.

At the end of the day, the results showed that half the students in the morning lied and majorly picked the side that would get them more extra credit. In the afternoon, that number shot up to 63 percent.

One of the students in the afternoon who solely picked the right side of the screen, no matter what to get more extra credit, said she may have been more honest in the morning.

"I think I may not have paid as much attention to what you were saying, and just paid attention to right left just paid solely attention to the dots and maybe not the numbers of extra credit," Rachel Vander Till said

And when a detective at the Meridian Police Department was asked if this theory would affect how polygraph professional did their jobs, Detective Eric Stoffle said he never thought of that before.

"We basically do the tests when we can get them done, when somebody's willing to come in, and we try to accommodate people and their schedules," Stoffle said. "It's never occurred to me that there might be a better time of the day to do a polygraph examination."

But Detective Eric Stoffle said tiredness is one thing they do check for before doing the polygraph examination.

"We're very careful when we do polygraph examinations; we make sure the examinee is able to take the polygraph examination, that they're not too tired to examinate," he said.

And the department relies on more concrete indicators to determine whether someone is lying. The polygraph chair uses finger sensors to measure how much the person sweats, an arm band to measure their heart rate, two bands across the chest to measure breathing, and a seat cushion to see if the person fidgets.

"In a single issue test, which we would use for a criminal investigation, where we're just talking about one thing, asking questions about one thing, (the tests) are 90 percent or better in accuracy," Detective Stoffle said.

And if hooking someone up to a machine isn't an option, Christine Moore, who teaches a lecture on the body language of a liar, says there really isn't a foolproof way of knowing if someone is lying.
"Without any technological help, like a lie detector test... If it's someone you're not familiar with, you have about a 50 to 60 percent chance that you can tell that they are lying," Moore said.

So it might be best to ask the questions you want answered truthfully in the morning.