Lance Armstrong's first Tour de France performance back in 1999 was so astounding that right away, people suspected he was doping. That's an allegation he denied then, and continued to deny for the next 13 years.

The idea that lying gets easier over time, and that a tiny fib can escalate into a bigger lie, has been around for a long time. But it's never been proven scientifically until now. And the results are out in this week's issue of the journal Nature Neuroscience.

Dr. Neil Garrett, who was a Ph.D candidate in experimental psychology at University College London in the UK, but is now at Princeton University doing his postdoc, led this study looking into what's going on inside our brains as we lie repeatedly. While at first it might feel bad to tell a self-serving lie, the more a person does it, the easier it gets. And the easier it gets, the more lies can escalate.