WASHINGTON — Telling little fibs leads down a slippery slope to bigger lies — and our brains adapt to escalating dishonesty, which makes deceit easier, a new study shows.

Neuroscientists at the University College London’s Affective Brain Lab put 80 people in scenarios where they could repeatedly lie and get paid more based on the magnitude of their lies. They said they were the first to demonstrate empirically that people’s lies grow bolder the more they fib.

The researchers then used brain scans to show that our mind’s emotional hot spot — the amygdala — becomes desensitized or used to the growing dishonesty.

“You can think of this as a slippery slope with what begins as small acts of dishonesty escalating to much larger ones,” said study lead author Neil Garrett. “It highlights the potential dangers of engaging in small acts of dishonesty on a regular basis.”

“The more we lie, the less likely we are to have an emotional response” — say, shame or guilt — “that accompanies it,” said lab director Tali Sharot.