Teenage rebellion

A documentary called Walking with Beasts is talking about how a mother kicks her child off on his own. This is a programmed action. Human children tend to kick themselves off on their own.

Teenagers are probably programmed by nature to rebel to some degree so that they will go out on their own rather than repeating possible mistakes of parents. If nature programmed them to be this way, there probably was an advantage to it. Otherwise, nature could have programmed them to be less rebellious in general.