People may lie to appear honest if events that turned out in their favor seem too good to be true, according to new research published by the American Psychological Association.

"Many people care greatly about their reputation and how they will be judged by others, and a concern about appearing honest may outweigh our desire to actually be honest, even in situations where it will cost us money to lie," said lead researcher Shoham Choshen-Hillel, PhD, a senior lecturer at the School of Business Administration and Center for the Study of Rationality at The Hebrew University of Jerusalem. "Our findings suggest that when people obtain extremely favorable outcomes, they anticipate other people's suspicious reactions and prefer lying and appearing honest over telling the truth and appearing as selfish liars."

The study found similar findings about lying to appear honest in a series of experiments conducted with lawyers and college students in Israel, as well as online participants in the United States and United Kingdom. The research was published online in the Journal of Experimental Psychology: General.

In one experiment with 115 lawyers in Israel, the participants were told to imagine a scenario where they told a client that a case would cost between 60 and 90 billable hours. The lawyer would be working in an office where the client wouldn't know how many hours were truly spent on the case. Half of the participants were told they had worked 60 hours on the case while the other half were told they worked 90 hours. Then they were asked how many hours they would bill the client. In the 60-hour group, the lawyers reported an average of 62.5 hours, with 17% of the group lying to inflate their hours. In the 90-hour group, the lawyers reported an average of 88 hours, with 18% of the group lying to report fewer hours than they had actually worked.

When asked for an explanation for the hours they billed, some lawyers in the 90-hour group said they worried that the client would think he had been cheated because the lawyer had lied about the number of billable hours.

In another experiment, 149 undergraduate students at an Israeli university played online dice-rolling and coin-flipping games in private and then reported their scores to a researcher. The participants received approximately 15 cents for each successful coin flip or dice roll they reported. The computer program was manipulated for half of the students so they received perfect scores in the games, while the other group had random outcomes based on chance. In the perfect-score group, 24% underreported their number of wins even though it cost them money, compared with 4% in the random-outcome group.

"Some participants overcame their aversion toward lying and the monetary costs involved just to appear honest to a single person who was conducting the experiment," Choshen-Hillel said.

In another online experiment with 201 adults from the United States, participants were told to imagine a scenario where they drove on many work trips for a company that had a maximum monthly compensation of 400 miles. They were told that most employees reported 280 to 320 miles per month.

Half of the participants were told they had driven 300 miles in a month while the other half were told they drove 400 miles. When the participants were asked how many miles they would report, the 300-mile group told the truth and reported an average of 301 miles. For the 400-mile group, the participants reported an average of 384 miles, with 12% lying and underreporting their mileage. There were similar findings in another online experiment with 544 participants in the United Kingdom.

Choshen-Hillel said she believes the study findings would apply in the real world, but there could be situations where the amount of money or other high stakes would lead people to tell the truth even if they might appear dishonest.

"While our findings may seem ironic or counterintuitive, I think most people will recognize a time in their lives when they were motivated to tell a lie to appear honest," she said.