Don't take this the wrong way.

Human beings are inherently stupid. Don't take take this the wrong way.

Say you put a newborn baby, and left it in a wolf den next to a wolf-mom and her new born cubs. In 18 years of so, if the baby makes it, it will be fully grown. By this time it will think it is a wolf. It will not be, in our view of the term, human. It will be homo sapiens, but try shaking its hand and it will probably bite you.

Nurture 1, Nature 0.

Everything you know; etiquette, fire is hot, how to say ahhh, stars are faraway suns, your religious beliefs (or lack thereof), food goes in your mouth, etc; is NOT instinct.

This knowledge has slowly accumulated as humans have grown up through the ages. Without society to teach and remind us of these common facts, we would revert to a near-animal form.

People will believe anything if that is all there is to believe. Isolate a large group of people for enough generations, let knowledge of the outside world slowly fade and contrary to what you may hope, society's norms will not survive.

Don't believe me? Take the time where a married couple locked their kid in their house and made it so he couldn't see out through the windows. How did they stop him from just opening the door and walking out? They told him he was on a space ship in the vacuum of space. Not strange enough? Oh yah, they only talked to him in Klingon, the Vogon language from Star Trek. When the kid eventually got out (I think he was a teenager), he could only speak Klingon and had no clue what a date was (the word doesn't exist in Klingon). [1] [2]

You think we have inbuilt morals?
You think we have instincts?

Think again.