Shakespeare once wrote: "Though I am not naturally honest, I am so sometimes by chance." As usual, he was a keen observer of human behaviour because research findings indicate that most people tell one or more lies every day (DePaulo & Kashy, 1998). In fact, diary studies in which individuals describe their own behaviour indicate that people use deception in almost 20 percent of their social interactions, and experiments indicate that a majority of strangers lie to each other at least once during a brief first encounter (Feldman, Forrest, & Happ, 2002; Tyler & Feldman, 2004). Why do people lie? For many reasons: to avoid hurting others' feelings, to conceal their real feelings or reactions, to avoid punishment for misdeeds.In short, lying is an all-too-common part of social life. - Social Psychology (Twelfth Edition) by Robert A Baron, Nyla R Branscombe, & Donn Byrne
What does this excerpt tell us about "human nature"? We want to fit in - we want to be liked - for the most part, anyway.
Why else would we hide our true feelings and thoughts? Not wanting to hurt someone else's feelings amounts to the same thing: not wanting them to dislike us. The most honest people are usually judged quite harshly and do not fit in. We have become so used to being dishonest that honesty is something of a foreign concept, an unusual occurrence to which we are quite sensitive and likely to take personally.
We live in a house of cards, each card a perfectly constructed and placed half truth, omission or flat out lie. Too much honesty and our house would come crumbling down around us. Our functioning depends on us maintaining our murky worldviews and lack of curiosity about how things (really) work. We have developed all kinds of "professions" that validate our current worldviews: psychology, philosophy, economy. How much of what these professions claim to be true (or possible) would be agreed with if some other intelligent life were to be made aware of it? Not much I'd wager. A lot of what these professions profess is dependent on the continued dishonesty of humans. The only way any of us believe it is by being willing to not ask questions.
We don't like experiencing pain and other "negative" feelings. In fact, we will pretty much do anything to avoid negative experiences - we much prefer feelings of happiness and bliss. Going against the norm brings some seriously negative experiences to a person - at least if that person is in the habit of wanting to fit in and feel accepted and loved. If you go against the grain then you know that there is some unpleasantness coming your way: people tend to reject and punish that which challenges their happy lives of murky half-truth waters. We like to take the road of lead resistance in life - the road that will have the least hurt. Sometimes this requires dishonesty on our part, as well as a willingness to accept the dishonesty of others - live and let live - so that we can all remain happily dishonest together.