A new study has found that cheaters will remain cheaters with those who have been unfaithful in their first relationship being three times more likely to cheat in the next relationship.

The findings are based on a study of 484 participants in mixed gender romantic relationships. Participants were asked: Did they have a sexual relationship with someone that was not their partner? and Did they have suspicions of cheating in all of their relationships?

Those who were cheated on and knew it were twice as likely to allow it happening again in their next relationship. Suspicious people, who could not shake the feeling, were four times more likely to accuse their partners of infidelity in later relationships. The study was originally published in the journal Archives of Sexual Behaviour.

So why is it hard for people to stop cheating? Because our brains get used to lying when we do it often, according to a study published in Nature Neuroscience. Our brains become numb to small lies as it is associated with negative emotions. Which is why we may be encouraged to tell bigger lies later in life.

“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,” researcher at Princeton Neuroscience Neil Garrett said.

“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,” he added.