'Once a cheater, always a cheater' is TRUE: Scientists reveal those who have been unfaithful will do it again - because their brains become immune to lying

  • People who have been unfaithful in the past are far more likely to do it again 
  • Even if a cheater feels guilty about lying, they are less likely to the next time 
  • Brain scans in London study show they become desensitised to deceiving
  • Another study shows past cheaters are three times more likely to cheat again

The old adage 'once a cheater, always a cheater' may have some truth in it, according to a new study.

People who have been unfaithful in the past are far more likely to do it again - compared to those who have always been faithful. 

Researchers say this is because infidelity desensitises the brain from the negative emotions linked to lying.

Therefore, even if a cheater feels guilty about lying the first time, they are less likely to experience the same level of regret the next time around.

The study was  published in the journal Nature Neuroscience.

Research suggests if a person has cheated in a relationship in the past they are far more likely to do it again (file photo)

Research suggests if a person has cheated in a relationship in the past they are far more likely to do it again (file photo)

Study co-author Neil Garrett, a psychologist at University College London, told Elite Daily: 'What our study and others suggest is a powerful factor that prevents us from cheating is our emotional reaction to it, how bad we feel essentially, and the process of adaptation reduces this reaction, thereby allowing us to cheat more.

'With serial cheaters, it could be the case that they initially felt bad about cheating, but have cheated so much they've adapted to their ways and simply don't feel bad about cheating any more.'

THE KEY REASON WHY MILLENNIALS CHEAT IS TO FEEL A BOND

Infidelity can often leave the betrayed partner wondering why their spouse ended up straying.

Now, new research has identified two key reasons why millennials are likely to cheat and it's all to do with independence and interdependence.

An overwhelming majority of those questioned - 73 per cent - chose interdependence as their reason for cheating: trying a new person to see if they can satisfy what's lacking in their current relationship.  

Meanwhile, around 20 per cent of people felt their need for independence motivated their betrayal, according to the study published in the Journal of Sex Research. 

Other reasons for committing infidelity included consuming alcohol and seeking a thrill. 

Infidelity in this age group was found to be most common because millennials - typically defined as people currently in their 20s or sometimes up to mid 30s - are trying to sort their adult life out, the team from the University of Tennessee said. 

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How the research was carried out 

When we deceive someone, the part of the brain that regulates emotion - called the amygdala - is activated, and we can feel shame or guilt.  

Dr Garret’s team asked participants to play a game where they would sometimes get more money for lying to their partner.

They were shown a jar full of coins and asked to help a partner guess how many were in the jar.

The partner was only shown a blurry image of the jar.

But when they were told they would be rewarded if their partner over-estimated the amount of coins in the jar they were more likely to lie.

Brain scans of the volunteers confirmed that lying can be a slippery slope: people did lie more over time. 

Their brains got desensitised to deceiving, and how much they were desensitised could predict how much more someone would lie the next time.   

Their past does matter

Another recent study found similar results. 

Researchers discovered those whose previous partners had been unfaithful before are twice as likely to be cheated on again, according to a paper published in the journal Archives of Sexual Behaviour.

That research looked at 484 participants of mixed-gender relationships and their sexual relations with someone other than their partner.

The results showed that people who had cheated in their first relationship were three times more likely to cheat in their next relationship compared to those who had stayed faithful. 

And it also discovered that suspicion of cheating worsens over time.

Those who have suspected being cheated on in the past were four times more likely to accuse future partners of cheating, regardless of whether they had cheated or not.

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