Have scientists found a way to make you tell the truth? Stimulating the brain with electrodes can increase honesty

  • In an experiment, participants could increase their earnings by cheating
  • Researchers found most people in the game cheated to make more money 
  • Non-invasive stimulation of the brain led to participants being more truthful
  • But the method only works on people with a moral compass, researchers said

By Daisy Dunne For Mailonline

Published: | Updated:

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.

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Running a non-harmful electrical current through the brain could make people more honest, researchers have found (stock photo)

Running a non-harmful electrical current through the brain could make people more honest, researchers have found (stock photo)

THE EXPERIMENT 

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. 

The researchers then stimulated a brain in a region of the right dorsolateral prefrontal cortex (rDLPFC), which thought to play a role in the deliberation process between selfishness and honesty.

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.

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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'. 

Scientists have identified the brain mechanism that governs decisions between honesty and self-interest (stock image)

Scientists have identified the brain mechanism that governs decisions between honesty and self-interest (stock image)

ARE PEOPLE WHO SWEAR MORE HONEST? 

A recent study found people who liked swearwords and used them most often were least likely to lie. 

People who swore more on Facebook also lied less often online to make themselves look better.

Co-author David Stillwell, from the University of Cambridge, said: 'There are two ways of looking at it. 

'You might think if someone is swearing a lot, this is a negative social behaviour seen as a bad thing to do, so if someone swears they are probably a bad person as well.

'On the other hand, they are not filtering their language so they are probably also not putting their stories about what is going on through similar filters which might turn them into untruths.

'That is what we seemed to land on in this study, that people who use the language that comes to mind first are less likely to be playing games with the truth.'

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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.

'These brain processes could lie at the heart of individual differences and possibly pathologies of honest behaviour', said Professor Ruff.

The new results raise the question of to what degree honest behaviour is based on biological predispositions.

Professor Maréchal said: 'If breaches of honesty indeed represent an organic condition, our results question to what extent people can be made fully liable for their wrongdoings.'

The research was published in the Proceedings of the National Academy of Sciences.

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