Children are not pliant clay that can be made into anything the parent chooses. Children are not mercenaries who can be bribed into goodness. Children are offspring of God with divine natures and eternal destinies. It is an earthly parent's job to help each child discover the full expression of his or her divine mission. Learning theorists often claim research as an ally.
Research reportedly shows that only their approach can reliably change behavior.
That has been demonstrated repeatedly in the lab. But they are effective because they first reduce us to the level of animals and they reduce desired change to microbehaviors. The tools of behaviorism work best with pigeons and rats. If our goal is to cultivate divine nature, such tools are insulting and insufficient, even counterproductive. Since our eternal missions are written in our souls, rewards are merely a disgraceful distraction from the still, small voice.