"Your cheatin' heart will make you weep," as Hank Williams once sang, and we all want to believe that it's true. Whether we're talking about a college student with exam answers written on his hand, or a tax cheat who's avoided paying the government, we want them to feel tormented by their own acts of duplicity, and sorry that they've pulled the wool over someone's eyes.
They problem is that they aren't. Instead, as a study recently published in the Journal of Personality and Social Psychology found, people who get away with cheating are likely to feel pretty good about it, as long as they're convinced no one has been hurt by their dishonesty.
The study's lead author, University of Washington business school post-doctoral researcher Nicole E. Ruedy, noted that dishonest people actually may experience what she called a "cheater's high" after doing something unethical.
"People expected an increase in negative emotion, or maybe a mix of negative and positive emotions, but that's not what we found," Ruedy explained. "Instead we found positive emotion, without accompanying guilt, shame or anxiety."
And that raises an even more intriguing question. Is our penchant to feel good about dishonesty something that we learn through experience? Or is "cheater's high" a capability that was hard-wired into our brains by evolution, because happy liars gained a competitive advantage over more morally conflicted humans?
There is considerable evidence that our ability to tell lies is evolutionary in origin. Other animals also practice deception -- Rhesus monkeys, for example, hide food to avoid having to share it with other monkeys.
Andrew Byrne and Nadia Corp, researchers at the University of St. Andrews in Scotland who've studied primate prevarication, have found that the capability for foisting falsehoods upon others appears to be linked to brain development. The size of the cortex, the outer brain region where advanced cognitive functions takes place, is a good predictor of how skilled a particular species will be at being untruthful.
"If you look around the animal world, deception is widespread, from small organisms to large ones," explained Kang Lee, a psychologist and professor at the University of Toronto, who has studied the development and frequency of lying in children.
In addition to enabling animals to fool predators, deception also helps members of a species to compete against one another for needed resources. "Humans are doing the same thing."
We also know that humans display the ability to deceive at an early age.
A 2007 study by Vasudevi Reddy, a psychologist at the University of Portsmouth in Great Britain, found that babies as young as 6 months feigned distress by crying in order to get attention from their mothers, and actually paused to see whether their mothers responded before crying again.
"We are not born liars, but we're born with the abilities we need to lie effectively, so that when the time comes, we can use them," said Lee, who also has studied young children's use of falsehoods. Those innate skills, he said, include the ability to control our own behavior, and the ability to perceive others' reactions and infer what is going on in their minds.
Lee has found in his research that by age 12, nearly all children lie, though the proportion of deceivers drops off to about 70 percent by age 16.
We also know that lying may have some relationship to brain anatomy. A study by University of Southern California psychologists, published in the British Journal of Psychiatry in 2005, found that people who habitually lie, cheat and manipulate others actually have structural differences in their brains.
MRIs showed that they had 22 percent more prefrontal white matter -- essentially, wiring of the brain's network -- than a control group, which the researchers suspected gave them more sophisticated verbal skills, and added capability for juggling the complexities of a deception. At the same time, chronic liars also had 14 percent less gray matter, the material that enables the mind to, among other things, process moral issues and make judgments.
The ability to lie seems to have emerged at the same point in our history as the development of complex social structures, scientists say, and it may actually be crucial to human society. Lee noted that it enables people to get around restrictive rules set by the group, without being shunned or expelled for their transgressions.
But paradoxically, lying also helps keep the group together. "White lies are an example of this," he said. "We use them to avoid hurting others' feelings, which would not be good for group cohesiveness."
A 2013 paper by Trinity College researchers Luke McNally and Andrew L. Jackson, published in Proceedings of the Royal Society B, suggests that the ability to deceive may have evolved in parallel to the human ability to cooperate. Cheaters, in their model, won out in natural selection because they were better at tricking other humans to cooperating with them, even if they weren't actually behaving cooperatively.
If lying is indeed an evolutionary adaptation, it might be that "cheater's' high" has evolutionary roots as well, since a person who felt good after committing acts of dishonesty would have an incentive to repeat the behavior. "It could reinforce unethical choices, which is one of the more disturbing implications of the study," Ruedy noted.
However, if there's a saving grace, Ruedy noted that her subjects experienced "cheater's high" in the immediate wake of their dishonest acts, and that it may turn out to be a transitory phenomenon that eventually gives way to guilt and remorse.
"If there's an evolutionary reason for cheater's' high, that might also be the reason why the reaction changes over time," she said. Feelings of remorse might put just enough of a brake upon dishonesty to discourage most people from practicing it all the time.
Additionally, limiting the amount of dishonesty reduces the cognitive demands of maintaining falsehoods, and actually helps make the occasional deception more effective, Lee explains. "With a low-probability event, people have more difficulty detecting it," he said.