A study by Doctor Isabel Thielmann (Germany) and colleagues, published in May/2025 in the Journal of Personality and Social Psychology, found that those who are dishonest in one instance have a 44% chance of being dishonest in subsequent actions.

Conversely, those initially honest have only a 6% chance of engaging in deceptive behavior. Notably, the "dark factor" personality trait is clearly linked to repeated dishonest behavior. Individuals with a higher dark factor score are more prone to dishonesty across various tasks.

The study concludes that those who have been dishonest are likely to continue being dishonest. This isn't random behavior but rather a sign of a stable personality trait. When dishonest in financial matters, they are also dishonest in relationships.

Some studies show that those who have been unfaithful are likely to be unfaithful again. Photo: Adajennifer

Some studies show that those who have been unfaithful are likely to be unfaithful again. Photo: Adajennifer

A 2018 study also showed that those who had been unfaithful were three times more likely to repeat the behavior. Scientists believe this is not just due to circumstances, but is rooted in genetics.

Specifically, a variant of the "thrill-seeking gene"—related to dopamine sensitivity, the neurotransmitter responsible for pleasure and motivation—is involved. Those with this gene variant experience less satisfaction from ordinary experiences, leading them to seek stronger stimuli like alcohol, gambling, or infidelity.

When faced with a choice between honesty and dishonesty, the brains of frequent liars react differently: The areas associated with self-reflection are less active. This makes them less likely to consider the ethical implications and impact on others.

However, scientists emphasize that genes do not determine everything. Many people with the thrill-seeking gene variant remain faithful, while many without it are unfaithful.

According to therapist Renee Zavislak, serial cheaters often exhibit a lack of empathy, arrogance, and a tendency to manipulate for personal gain. These traits often arise from a combination of biological factors and childhood trauma such as rejection or abandonment.

Doctor Cammy Froude suggests that narcissistic individuals may view infidelity as their right and feel no guilt because they don't empathize with others. They believe the rules don't apply to them.

However, Doctor Kayla Knopp, a relationship psychologist in the US, cautions against hasty conclusions. According to her, infidelity is not a fixed trait but a behavior influenced by society, especially the norms of monogamy.

"For some, infidelity stems not from inherent wrongdoing, but from a mismatch between expectations and individual personality. If they were in a more suitable relationship model, they could be more honest and happy," she said.

Bao Nhien (Psychology Today/ Dailymail)