still no, but it happens and its horrible.
Teenagers often engage in this behaviour as a pack. To better their social standing? Mindlessly? To better their own self esteem? Because they are learning manipulation and see it as desirable?
Then there are adults who engage in this to better their own self esteem.
Its a sad practice, and i cant imagine any circumstance in my life where i would desire to engage in it myself.
I would say it generally lies in weakness of character by the perpetrator.