Some people, even some very young people, just can't be helped.

Honestly, though, my normal belief is that children, like cats and dogs, aren't the problem. If your dog shits on your bed, that's not the dog's fault - and if your child does the same thing, either your expectations are too high, or there's some serious issue going on that is Not The Kid's Fault.

Which doesn't make dealing with them any more pleasant, of course - it just means I get to feel bad when I label some kid in my mind as a brat.