An unsupervised five-year-old will let a stranger indoors, take candy from a stranger, play with a gun he finds etc. no matter what you drill into him.
I don't believe I would have done any of those things - and my parents would agree. Comprehension and implementation of rules was well within the realm of my capabilities and I was only rebellious against or defiant of rules I thought were stupid. Not those that could be explained ("that is dangerous and kills people") or those that I was already indifferent to (I would only have answered the door out of a sense of obligation or kindness anyway, I certainly wouldn't have wanted to.)
"No matter what you drill into him" sets a fairly high bar of stupidity.
An interesting blog post by Razib Khan, who many here probably know from his Gene Expression blog, the old gnxp site or perhaps from his BHTV debate with Eliezer.
I recommend following the link and reading the rest of it there, not only does interestingness continue, the comment section there is usually worth reading since he vigorously moderates it.