Trending Science: The more you lie, the easier it gets

If you lie once, you’re probably likely to lie again. This is the blunt conclusion of a study recently published in the journal ‘Nature Neuroscience’. In essence, telling small, insignificant lies desensitises the brain to dishonesty, meaning that lying gradually feels more comfortable over time.

‘Whether it’s evading tax, infidelity, doping in sports, making up data in science, or financial fraud, deceivers often recall how small acts of dishonesty snowballed over time and they suddenly found themselves committing quite large crimes,’ commented Tali Sharot, a neuroscientist at University College London (UCL) and senior author of the study.

When we deceive someone, the part of the brain that regulates emotion – called the amygdala – is activated and we often feel shame or guilt. The amygdala also responds when we see images that make us happy (for example, the latest viral cute cat video on YouTube) or sad. It has already been shown that when our brains see these cute or sad images over and over again, the amygdale reacts less and less each time. The UCL team wanted to see if this would be the same case with lying.

80 volunteers were picked for the study and had a play a game in which they estimated the values of pennies in a jar and sent their guess to an unseen partner. Sometimes the volunteers were told they would secretly benefit at their partner’s expense if they overestimated the money in the jar, which incentivised them to lie. Other times, they were told that both they and their partner would benefit. The unseen partner though was in fact an accomplice of the research team.

At first, volunteers tended to alter the jar’s value by around GBP 1, but this typically increased to around GBP 8 by the end of the session. 25 of the volunteers played the game whilst being monitored by an MRI scanner. As the participants continued to lie, the research team saw that the amygdala’s response gradually declined.

What was also very interesting to the team was the fact that participants kept lying to help themselves even if lying didn’t lead to greater monetary gain every single time. This means it is more likely that people kept lying not because of rational calculation but because their brains became physically desensitised to the very act of lying. However, it is important to note that predicting future behaviour did not work for all participants but the general trend was indeed there.

There are some limitations to the study though – the study tested only one particular game, so it’s uncertain how people would react in other situations where dishonesty is involved. And even though the experiment took place in a controlled laboratory environment, the downside is that it’s difficult to ascertain whether the same biological trend would occur in real life situations. Also, MRI scans may not be as accurate as expected – just because one part of the brain records less activity, this doesn’t mean that the person didn’t feel guilt for lying, with the researchers themselves unable to enquire about this as then it would have given away the game entirely.

However, the research team is confident that their results indicate the existence of a ‘slippery slope’ scenario, where the first lie instils guilt but if there are no negative consequences as a result, by the third lie we’re used to it. The team has speculated that the amygdala activity could represent the internal conflict between one’s desire to be seen as honest and being tempted to lie and serve one’s best interest as a result. This would fit their observation that people appeared to lie more when it benefited both themselves and their partner – perhaps because it was easier to justify a lie that served the common good?