There might be a biological process behind lies. A study published Monday in the journal Nature Neuroscience suggests that the part of the brain that activates with emotions such as shame and guilt reacts less the more people lie.

Everyone knows that a little lie leads to bigger ones, but this is the first time a research team came up with biological evidence to support that theory. Titled “The Human Brain Adapts to Dishonesty,” the paper explains from a biological perspective that deceit becomes easier the more people lie and that those who lie once are probably more likely to lie again.

lying-brain
Your brain could be actually causing you to lie. Image Credit: Brock University

Deep in our temporal lobes, the amygdala, was the predominant region of the brain playing a role in the process of lying. The neuroscientists at the University College London focused on that area and found that it produces a negative feeling that “limits the extent to which we are prepared to lie,” as reported by CNN.

Tali Sharot, an associate professor of cognitive neuroscience said the amygdala’s response faded as the study participants continued to lie, which resulted in bigger lies. Sharot added that this finding could serve as an explanation for the “slippery slope” of lying.

The researchers wanted to know if the amygdala reacted when people lied just as it activates when they see cute cats or puppy pictures, or very sad movies. When the brain is exposed to an emotional stimulus, again and again, the amygdala’s reaction fades.

“If someone lies repeatedly, they no longer have an emotional response when they lie,” explained Sharot, as reported by CNN. “In absence of an emotional response, they feel more comfortable and lie more.”

This concept also serves to explain other cases in which individuals adapt to a given circumstance, according to Sharot. For instance, people usually adjust to a very cold pool after a while and gruesome pictures as easier to look at after several times.

Brain scans during a game

Neuroscientists at the University College London’s Affective Brain Lab arranged for 80 adults to go through an experiment involving scenarios where they could be financially rewarded as they repeatedly lied to their partner. The study participants were asked to play a game in which they would see a photo of a jar filled with pennies and advise a partner in a separate room about the amount of money they should guess was in the pot.

The research team exposed the subject’s partner to a photo that was less clear so they would need the advice of the other participant. The subject was paid more as they said bigger lies so their partner would overestimate the bonus.

None of the study participants were told to be dishonest. In one version of the game, the researchers told the test subject that he and the partner would both share in overestimating rewards. In another version, the test subject was the one who would get most of the money by overestimating. The first case resulted in bigger lies coming from the subject.

The participants started by lying on average worth 4 British pounds (about $5) at the beginning and escalated to about 8 pounds ($10) near the end of the experiment after 80 repetitions.

The researchers then chose randomly 25 test subjects and used an MRI machine to scan their brains. By doing so, they found that the amygdala did react less as the participants said bigger lies.

The test subjects continued to lie even if that didn’t help them make more money in every repetition, which shows that those who constantly lie may not always do it because of rational calculation. Here is where the amygdala plays an important role as it activates less when individuals get used to being dishonest, and they stop feeling guilt or shame.

Sharot compared this with people who have used the same perfume for years and start using more over time as they stop noticing the smell.

“You can think of this as a slippery slope with what begins as small acts of dishonesty escalating to much larger ones,” said study lead author Neil Garrett, now a neuroscience researcher at Princeton University, as quoted by the Washington Post. “It highlights the potential dangers of engaging in small acts of dishonesty on a regular basis because these can escalate to much larger ones further down the line.”

Although this study was carried out in a controlled lab setting, Garrett said similar cases might take place in real-world scenarios such as politics and infidelity. However, further research is needed to be able to know for certain that people in real-life situations also get used to lying as their amygdala’s reaction fades.

What other researchers think of this study

Robert Feldman from the University of Massachusetts, who teaches psychology and brain sciences, said these study findings provide a better understanding of the way people become better at lying the more they practice, according to the Washington Post. He added that this research warns that tolerating white lies can result in greater levels of dishonesty.

For his part, Shaul Shavi, head of the Behavioral Ethics Lab at the University of Amsterdam, said this is the first evidence to show the slippery slope in lying and described the study as “elegant.” And Maurice Schweitzer, who studies deception at the University of Pennsylvania’s Wharton School of Business, said the method with the brain scan was novel, as reported by The Post.

Neuroscientist and professor of psychology at Northeastern University Lisa Feldman Barrett believes the study is rather incomplete, CNN said. While the study authors focused on the amygdala as a source of emotion, she thinks that this part of the brain is not necessarily critical for such a process based on evidence showing that people can feel emotion without changes in the activity of the amygdala.

Although that region is often involved during emotions, even individuals who don’t have it do feel emotion. She added that the amygdala could also activate when people feel interested in something and that it is also linked to memory, perception, and social interaction.

Her point is that habituation may play an important role in lying, but she also remarks that there might be other sources of emotion different than the amygdala that would be worth looking at.

Source: Washington Post