People who tell little white lies that "don't hurt anyone" are going to hate this study.

Small lies are so easy. We use them to avoid pain, dodge conflict, save time.

“Borrowing” $20 from your mother’s purse in high school. Telling friends you’re bed-ridden with the flu when you’re secretly just watching Netflix and you don’t want to leave the company of your hot water bottle. Small lies slip out almost without us realising. We tell them to increase our own comfort, enhance the way we’re perceived by others, even improve our situation financially.

But all these small, seemingly harmless “white” lies are leading to a bigger problem.

New research, out of the University College London, shows telling little lies desensitises our brain to dishonesty.

Researchers monitored the brain activity of 80 participants as they told lies for financial benefit. The scans showed how activity in the emotional cradle of the brain – the amygdala – changed as participants lied, and then lied again and again.

Typically, lying involves a physiological response. Blood rushes to the amygdala and it lights up with activity. These are the feelings of guilt and shame and “will they find out, don’t look away, don’t look away, everyone knows you’re lying when you break eye contact” that accompany lies from novice lairs.

More experienced lairs, however, have a ‘seasoned’ amygdala. It’s seen a lot more. The research found that, the more a person lies, the more the amygdala stays calm. The little voice of guilt in the brain goes quiet and lying becomes easier.

“The more we lie, the less likely we are to have an emotional response that accompanies it,” study co-author and lab director Tali Sharot told 

She described this as a “slippery slope” where white lies turn into real lies, which turn into big lies, which have the capacity to ruin friendships and darken relationships.

Basically “the dog ate my homework” could be a slippery slope.

Next time, I might just fess up about the Netflix watching. I don’t want to turn into a pathological liar. I like my amygdala just the way it is. Sensitive. Filled with rushing blood. And making my hands sweat.