Dan Ariely is probably one of the sharpest and wittiest scientist on earth. In this lecture he covers an interesting topic of how we lie.

Check out his lecture below:

Behavioral economist Dan Ariely studies the bugs in our moral code: the hidden reasons we think it’s OK to cheat or steal (sometimes). Clever studies help make his point that we’re predictably irrational — and can be influenced in ways we can’t grasp.
Ted.com