The greatest instinct is self-preservation, and we lie to protect ourselves. Some of the greatest documented cases spring from this. Why do we want to live? We wish to feel peaceful, happy, contented, serene ... and when these values are threatened, we do strange things.
I saw a movie last night where a fighter was the fifth best in the world. You would think that he would be satisfied. But he went away and trained really had for 10 years and returned to fight the one he had lost to. Turned out he wanted to be number one for name and fame.
Before the fight, his adversary made the philosophical comment that this was a strange world; that people would risk their lives, all because of name and fame. Yes, Grace, we do this a lot, and yes, we do lie.
By the way, Spirituality is the science that not only creates but enhances existence ... awareness. Nothing is without this in life. No, not psychology, or sociology or science ...they are all interwoven and all are useful in their own different ways. Much Peace.