Running a non-harmful electrical current through the brain could make people more honest, researchers have found.
Scientists have identified the brain mechanism that governs decisions between honesty and self-interest.
And tampering with this region using non-invasive brain stimulation could make people more likely to tell the truth.
The deliberation process between honesty and self-interest is controlled in the right dorsolateral prefrontal cortex (rDLPFC), according to the researchers.
In an experiment, participants were asked to take part in a game where they could increase their earnings by cheating.
Researchers found most people in the game cheated to make more money.
But some participants stuck to the truth.
‘Most people seem to weigh motives of self-interest against honesty on a case-by-case basis,’ said Professor Michel Maréchal from the University of Zurich.
‘They cheat a little but not on every possible occasion.’
They added that 8 per cent of people choose to cheat in every game, regardless of the potential rewards.
The researchers then stimulated a brain in a region of the right dorsolateral prefrontal cortex (rDLPFC).
This noninvasive brain stimulation, called transcranial direct current stimulation, uses electrodes to make brain cells more sensitive and more likely to be active.
When the researchers applied this stimulation during the task, participants were less likely to cheat.
But the number of serial cheaters remained the same.
Professor Christian Ruff said: ‘This finding suggests that the stimulation mainly reduced cheating in participants who actually experienced a moral conflict, but did not influence the decision making process in those not in those who were committed to maximizing their earnings’.
The researchers found that the stimulation only affected the process of weighing up material versus moral motives.
They found no effects for other types of conflict that do not involve moral concerns, including financial decisions involving risk, ambiguity, and delayed rewards.
Another experiment showed that the stimulation did not affect honest behaviour when cheating led to a payoff for another person.
These findings are an important first step in identifying the brain processes that allow people to behave honestly, according to the researchers.