The reason people lie could be driven by compassion but also selfishness. Say for instance I am married. I go out with some friends one night meet another woman and sleep with her. OK, Now when my wife asks me what I did the previous night I tell her some other random story other than the truth. I just lied. I did this I believe for a few reasons. I don't want her to feel hurt or upset, I dont want a divorce and I must really be into my wife since she is my wife. Maybe I was at a weak point...I don't know because I would never be in this situation. I probably will never be married because I am too honest. In the dating stage I would probably make some comment about some other girl that would make her fragile ego crumble and crawl away. But I believe these thoughts are just that. I happen to put them into words that may seem harsh, however its the truth and I feel its the only way to remain honest with myself and others constantly. I believe its when these things are bottled up is when they turn into actions. Isn't the real goal understanding? not ego boosting. To understand one another is ultimately what we all want. We want to be understood and we hopefully are curious to understand the people and events around us. Maybe that's it, Its the lack of wanting to understand. I lied to my wife because first of all I was too cowardly to talk to her about my feelings, And I was afraid of her reaction because I know that she wouldn't understand. However, All could have been avoided if both parties knew that the other would accept anything they had to say. Good or bad. Also to be able to sit down and try and understand and to express yourself deeply with one another. I know from personal experience its difficult to open yourself and become vulnerable. There are lot of insecurities and thoughts of what people will think of you. But, once that is overcome life is so super cool afterwards.
So, it seems people tell lies because they are to cowardly to open themselves and because they don't want to hurt the person they are telling the lie to. It just seems like the lies hurt worse than the truth. So in sparing someones feelings with a lie it would hurt far less to tell the truth.