Scientists identify the brain circuits that underlie dishonest decisions

Scientists have identified the brain circuits underlying dishonest decisions and discovered that the mechanism is not the same for everyone. On the contrary, it depends on individual personality and whether or not there is a reputational risk, namely if the lie is likely to be discovered.

The findings, published in the journal Communications Biology, have been obtained by a team of researchers led by Irccs Fondazione Santa Lucia and Sapienza University of Rome, and could also help develop strategies to promote more ethical and responsible behaviour in different social contexts.

The researchers, led by Lennie Dupont, involved 34 participants aged between 20 and 46 in a simple card game and monitored them using functional magnetic resonance imaging (MRI), a non-invasive technology that analyzes brain activity in real time by detecting changes to blood flow.

While a player outside the MRI tried to draw the winning card without being able to verify the result, the one inside the MRI instead had to communicate the outcome, deciding whether to tell the truth or lie for personal gain in the knowledge that in half the cases the fellow player might discover the deception.

As expected, participants tended to reduce self-interested lying when their reputation was at risk, but the results also showed that the activation of the brain circuits involved was not the same for everyone.