If you’re someone who doesn’t like lying, perhaps you’re not doing it enough.

A new study, published in the journal Nature Neuroscience, suggests that every time we avoid telling the truth, the negative emotions we experience when we lie get a little bit weaker.

So if we keep telling fibs, our brain becomes increasingly desensitized to the process.

“Think about it like perfume,” the senior author of the study, Tali Sharot, told the New York Times. “You buy a new perfume and it smells strongly. A few days later, it smells less. And a month later, you don’t smell it at all.”

Honesty jar

Participants in the study were asked to lie to a partner in another room about how many pennies were in a jar while their brains were scanned to assess activity in the amygdala, the area associated with emotion.

The study found that when the subjects first lied, they activated the amygdala, suggesting negative feelings about doing so. But each time the subjects lied about the money, the amygdala was activated less and less — which would make it easier for the person to keep lying.

Also, and perhaps unsurprisingly, when the subjects believed that lying about the amount of money was to their benefit, they were more inclined to dishonesty.

Slippery slope

The finding, the researchers said, provides evidence for the “slippery slope” sometimes described by those who have started out with a small lie, only to find it snowball into a career-ending web of deceit.

Sharot says: “They usually tell a story where they started small and got larger and larger, and then they suddenly found themselves committing quite severe acts."

The report also noted that the same gradual desensitization of the brain may also apply to risk-taking behaviour or acts of violence.