How does knowledge cleanse the mind?

The following is an excerpt from a samvaad (dialogue) session with Acharya Prashant.

Acharya Prashant (AP): Tell me, why does a small child get corrupted? The small child has — to begin with — no social influence upon him. He is like a little one emerging straight from the bathroom. With just the body and no influence upon the body. Right? Then why does he get conditioned and corrupted?