(Scientific American Mind)
The obvious question raised by all of this accounting is: Why do we lie so readily? The answer: because it works. The Homo sapiens who are best able to lie have an edge over their counterparts in a relentless struggle for the reproductive success that drives the engine of evolution. As humans, we must fit into a close-knit social system to succeed, yet our primary aim is still to look out for ourselves above all others. Lying helps. And lying to ourselves—a talent built into our brains—helps us accept our fraudulent behavior.