No, I’m not speaking of the motivation for lying – it is always, of course, the greed for the short-term benefits from not speaking the truth.  As most of us know, the long term harm from lying far outweighs any short term benefit.  Most importantly, it causes a loss of trust and how can you have a relationship with anyone when trust is not present.  Leading figures, from the Buddha, to Kant, Gandhi and many others have, therefore, taught that speaking the truth is important in all contexts.

However, despite the long term harm being well known to most adults, lying has not disappeared.  As people grow up, they know that lies get caught and they stop saying some obvious lies without stopping lying. Why?

My observation is that they can outsmart others and can lie so convincingly that they think they will not get caught.  And this is the reason they lie. 

And the reason they get caught in lies is that they were wrong – people around us are very smart relative to us and it is not, in fact, possible to keep the pretense.

I have heard objections of the type: “That’s not true.  For example, children know quite well that they’ll get caught but they’ll still say with ice cream on their face that they did not eat it – just to escape punishment or someone’s displeasure in the moment”.  That’s actually not a counterexample, but an example of the very thing I’m talking about.  Why do they stop saying it – because they learn that this kind of obvious lie does not fool anyone.  They then continue telling other lies that they think they can fool people with.

In summary, liars lie because they think they are smarter than those they’re lying to.  So next time when you tell someone a lie, remember that not only are you endangering trust and the relationship, you’re also implicitly insulting their intelligence.