Why would a parent shame their child for exploring their own bodies?  If the child gets caught doing so and the parent freaks out, what is the mental scarring that occurs?  From my experience I know that it could make one ashamed of their body.  It's natural to touch one's self.  It's also safer than actual sex as far as diseases go.  I approve of masturbation.  If I had a child and caught them doing it, I would just say "Oops, sorry, excuse me." and then close the door.  No one should be shamed for touching themselves unless of course, they do it in public.  To be made to feel as though the act is wrong is a shame in itself.