You know the worst part??? These kids are going to grow up and everyone is going to hate them and they are going to have no idea why because they have never been taught the proper way to behave.
I have a SIL who has 1 child like that...we affectionately call him The Spawn of Satan. The child has no discipline, no sense of conscience, no sense of right & wrong...it's deplorable. And all his parents do when he does something is say "He's 7"...duh!!!!!! I know he's 7 and when he's 7 is when you are supposed to be teaching him right from wrong!!!!!!!!!! In the next breath she says "he's gifted". Well, perhaps he is, but he's a little (censored) and will grow up with no friends because I can't imagine anyone tolerating him for any length of time. He has no friends now, and he's 7.
Someday I will be being interviewed on 60 Minutes about my nephew the serial killer, and you will hear me say "I knew from when he was a child that he'd grow up with problems".