I have been a keen observer in this matter and i think rather than need or fear it is a psychological disease just like kleptomaniac. Thanks
As others have said, we also lie to protect the ones we care about, or ourselves and friendships with them. As Dr. House says `Everybody lies.' Life is almost a joke. Designed to create twists and turns. We are weak and follow useless traditions, try to live up to unnatural ideals, and feel the need to want to trust others. God help us all.
It really depends on each case. Question is indeed very broad. It's just like asking "Why people go to cafe?" or "Why do we use Instagram". Lie can be the exception or the rule. When it's exception, people go out of comfort zone to lie, when it's the rule -- lie become a comfortable behavior itself. The reasons you mentioned above are also true, but they are not limited to it.
In evolutionary theory: Information is power. So there's selective pressure favoring those that can deceive detection while detecting deception. (But that's no comment on the morality of such behavior.)
Although it is believed that it is not good to lie, but it is simply impossible not to lie at all. One must at least strive to ensure that lies do not bring grief to others. But a little lie, that does not disappoint someone, is possible.
It is ok to lie to protect the honour of others. For example, sometimes I know people are off for a day of work for specific things, such as, applying for a job, going to the bank (loans), buying property. Telling everyone could cause problems. Others, may ask me if I know where they are. I simply say "up at the brothel", sometimes I say its "two for tuesday". Sometimes I say, "I dunno". Any knowledge I have is private, and I consider to be confidential. So I will lie, I will hide my knowledge in this regards. I think part of being a friend, and working closely with alot of others, is listening to their problems, and then remembering to forget.
I agree that people simply lie to entertain. Most people love mystery and what better way to become mysterious than to lie. It's also sort of like a defense mechanism. People don't like other people snooping around as our lives aren't always on a "need-to-know" basis.