© malerapaso/Getty Images The study suggests that telling small, insignificant lies desensitises the brain to dishonesty, meaning that lying gradually feels more comfortable over time.
American fraudster
Frank Abagnale, played by Leonardo DiCaprio in the film
Catch Me If You Can, started out swindling his father out of small change for date money and ended up impersonating an airline pilot, despite the admission that he "couldn't fly a kite".
Now scientists have uncovered an explanation for why telling a few
porkies has the tendency to spiral out of control.
The study suggests that telling small, insignificant lies desensitises the brain to dishonesty, meaning that lying gradually feels more comfortable over time.Tali Sharot, a neuroscientist at University College London and senior author, said: "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."
Sharot and colleagues suspected that this phenomenon was due to changes in the brain's response to lying, rather than simply being a case of one lie necessitating another to maintain a story.
In the study, published on Monday in the journal
Nature Neuroscience, 80 volunteers played a game in which they estimated the value of pennies in a jar and sent their guess to an unseen partner. Sometimes participants were told they would secretly benefit at their partner's expense if they overestimated the cash in the jar, incentivising them to lie.
Neil Garrett, also of UCL and a co-author, said: "We knew by how many British pounds they lied on each trial. The amount by which participants lied got larger and larger."
At first, volunteers tended to alter the jar's value by around £1, but this typically ramped up to about £8 by the end of the session.
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