You have been lied to sometime in your life. We all have been at a certain point. However, we have all lied too.
Lying, believe it or not, is a sign of intellect. Creatures that lack this amount of intellect are incapable of telling a lie. This is because lying demands creating a hypothetical scenario and predicting the outcomes.
Some people lie when it is necessary, however, some are addicted to lying and lie without any special reason.
Manipulators, narcissist and other people who want to take advantage of you can lie just so they get what they need from you.
Here is a brilliant infographic that beautifully describes the psychology of lying:
Source: Daily Infographic;