Once upon a time, long long ago, when I was very young, I heard about a family with two boys, very close in age - and polar opposites. The boys became teenagers, and got their drivers licenses. And then the REAL differences came out.
Boy 1: give him a curfew and a car, and he was home on time, but give him a curfew and no car, and he was late.
Boy 2: give him a curfew and a car, and he was late, but give him a curfew and no car, and he was home on time.
So, boy 2 complains that its "no fair" that HE doesn't get the car.
Discipline didn't work. At all. Not punishments, not rewards. Because it wasn't until 10 or 20 years later that the rest of the picture came to light...
The real issue? The group rules for their friends were different:
Boy 1's group: whoever has the car, sets the curfew, and everyone else goes home in time for driver to get home on time.
Boy 2's group: whoever has the car, takes everyone else home to meet their curfew times, and goes home last.
I guess, from the stories, these would both have been difficult children, but back then, both were considered "normal".
So, the problem is as old as the hills. If anyone finds the magic formula, they will become very rich. The rest of us... just keep trying.
In our house, we've thrown "discipline" out the window (<gasp!>), including the rule book and the punishments and the rewards. We have one set of "expectations" that apply to EVERY member of the household. Negative behaviour on all sides is dropping fast. We're getting way more compliance, with way less hassle. And it isn't supposed to work this way. So, go figure!