Since the early 1970s, the Oregon Social Learning Center in Eugene, Oregon, has treated hundreds of families with "prob- lem" children, children who bite, kick, scratch, whine, lie, cheat, and steal. As might be expected nowadays, this group of psy- chologists began with the assumption that the proper way to train difficult children is to reward their good deeds and ignore their bad ones.
The idea was, of course, that eventually the children would be so wrapped up in doing good that...