Scientists just discovered a key reason people might cheat - and it's in our biology

What explains dishonesty? When people are faced with the exact same opportunity to cheat, why do only some take the chance?

New research yields a potential answer.

According to the study, led by Jooa Julia Lee, Ph.D., a postdoctoral fellow at Harvard University, and cited on HBS Working Knowledge, certain hormones predict the likelihood that people will cheat. Moreover, acting unethically may be a way to reduce levels of stress hormones and alleviate experienced stress.

The researchers conducted two experiments designed to clarify the relationship between stress hormones and unethical behavior. In the main experiment, they asked 120 men and women to complete 20 math problems. All participants received $10 and were told that they would earn an extra $1 for every question they answered correctly.

Before and after the math test, researchers measured participants' levels of the hormones testosterone and cortisol using saliva samples. High levels of testosterone are known to increase sensitivity to reward and decrease sensitivity to punishment. And high levels of cortisol generally mean that you're stressed.

The participants were asked to grade themselves and report their performance. What they didn't know was that the researchers were able to assess their actual performance, so they knew exactly who had lied.

44% did.

The key discriminating factor seems to be participants' hormone levels. Participants who began the experiment with high levels of testosterone and cortisol cheated the most.

But here's the twist: The more people cheated, the more their levels of cortisol went down. When asked about their experienced stress levels, cheaters even reported that they were less stressed.

In other words, it seems as though some people cheated in order to reduce the stress they were feeling.

Based on their findings, the researchers say that some business environments may attract people who are likely to be dishonest.

"Many organizations base performance not only on incentives that increase stress and anxiety, which will elevate cortisol, but also on incentives that appeal especially to the highly ambitious, which will elevate testosterone," study co-author Robert Josephs, Ph.D., told HBS Working Knowledge. "These organizations are basically creating the perfect storm for the hormonal encouragement and maintenance of unethical behaviors."

Yet the study findings also suggest that people with certain hormonal compositions - namely high cortisol and low testosterone -might make better leaders. That's because they'd make wise decisions, but wouldn't be inclined to act unethically, Pranjal Mehta, Ph.D., a psychologist who was not involved in the study, told The Boston Globe.

One takeaway from this research is that when you are stressed, you should be extra cognizant of your own inclination to cheat. You might not be able to prevent the impulse from arising, but you can probably stop yourself from acting on it.