That's an interesting point. I wonder are we entirely dependent on learning boundaries between safe/unsafe from our parents going "darling, don't do that", if you know what I mean. I can't imagine the Dursleys spending much time protecting Harry - but then again the fact that he has survived until 11 without killing himself suggests that they must have intervened occasionally.

Equally, you could argue that a child who was never told not to do dangerous things would be more frightened - having learned the hard/painful way what the consequences of risky actions might be.

You've made me think a bit here. I'll go off and mull it over for a while :D