Source: NPR, Oct 2016
… the latest study, conducted by researchers from University College London and Duke University, set out to test whether telling small lies really did pave the way for telling larger ones.
when people first started lying — deceiving their partner in order to benefit themselves — the amygdala showed more activity. But the more the participant lied, the less active the amygdala got.
And the magnitude of self-serving lies grew with repetition. A participant who deceived his partner for a couple pennies many times was more likely to go on to deceive his partner out of more money in later experiments.
Sophie van der Zee at the Free University of Amsterdam in the Netherlands, explained it to the New Scientist, “When you lie or cheat for your own benefit, it makes you feel bad. But when you keep doing it, that feeling goes away, so you’re more likely to do it again.”