[ZenGum]

Purely theoretical thoughts here, as a non-parent:

Yep, a lot like puppy training - clear rules, consistent enforcement. And as Pooka mentioned, kids learn by copying their parents.

That said, some kids are just born weird. A cow orker of mine has a son who is ... problematic. Two parents, both conscientious at it, child is behaving like a classic psychopath. Recently their boy was at day-care. He has been a serial offender at physically stealing toys from smaller kids. He was seen last week stealing a toy from a babe (about 14 months) and holding his hand over the other kid's mouth so the carers wouldn't hear him wailing. Clever, shows he has theory of mind, but disturbing ... their boy is 18 months old!

Robert Hare, author of "Without conscience" and world expert on psychopaths, argues that while most psychopaths are "made" by childhood trauma and abuse, a fair number are born that way. It seems that emotion and empathy evolved as a way of engineering cooperation, but some people don't get the empathy thing working properly.

The case that started this thread doesn't sound like that, though. I think the problem there is that many people get into parenting either unintentionally, or without grasping just how much constant effort it takes. Half-assed parenting produces ill-behaved brats.