"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.