Science shows that telling small, white lies actually turns us into bigger liars

He makes it look so effortless. Science might explain why.
He makes it look so effortless. Science might explain why.
Image: Reuters/Joe Skipper
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The proverbial tangled web that grows from a small deception looks more like a slippery slope to neuroscientists.

A study published Oct. 24 in Nature Neuroscience has found that telling small lies makes its easier for people to tell even bigger fibs because the amygdala, the part of the brain that would normally put the brakes on a lie by making a person feel uneasy, gradually becomes desensitized to deception. The research is considered the first empirical evidence to show that lying actually gets easier with repeated fibs.

Neuroscientists at University College London came to this conclusion following an experiment involving 80 volunteers, 25 of whom had their brains scanned by an fMRI machine while they took part in a series of tasks that asked them to guess how many pennies were in a jar. The subjects looked at photos of different jars of pennies and were instructed to send their “advice” about how many pennies were in each one to a “partner,” who was actually working with the researchers.

To create the conditions in which lying would be helpful for personal gain, participants were offered varying cash-based incentives based on how they manipulated their estimates. In different scenarios, they were told that over- or underestimating the amount of pennies would either benefit them at their partners’ expense, benefit both participants, or serve their partners while harming themselves. The subjects believed their partners, who were unseen and supposedly working through a connected computer, were unaware of the carrots the researchers were dangling.

The scientists first established a baseline for brain activity by asking the subjects to make an accurate guess about the number of pennies. Then the subjects were told that slightly exaggerating an estimate would benefit themselves and not their partners. Among those who lied about their estimates, the brain scans showed a strong response from the amygdala, the part of the brain associated with emotion and known to produce negative feelings when one has crossed a moral boundary.

The researchers saw that as the wee lies for personal gain escalated into big, fat ones for greater rewards, activity in the amygdala dropped off. The scientists could even predict when a person was going to escalate his or her lies because the act would be preceded by more pronounced decline in amygdala activity.

“It is likely the brain’s blunted response to repeated acts of dishonesty reflects a reduced emotional response to these acts,” Neil Garrett, a neuroscientist at UCL and lead author of the study, said in a press report. He added that although they only tested dishonesty, “the same principle may also apply to escalations in other actions such as risk taking or violent behaviour.”

There was, however, a glimmer of hope about human nature in the study: The scientists found that people lied more when it would benefit both them and their partners than when they alone would profit.