Lying is usually brought upon by insecurity. Lies are told as an improvision to make up for shortcomings that the liar might experience. If they cannot face up to a situation, they will lie in attempts to save themselves. It's usually replaced in the instance of lack of self-confidence, etc. As the days go by, the world gets worse.
Most people are pigs, using any means to get what they want.
They'll lie to you, me, and anyone who gets in their way, just to climb up that ladder.