When it comes to parenting, it's funny how humor can motivate children when more negative tactics do not. Parenting guru Jane Nelsen, EdD, the author of dozens of books, including Positive Discipline and, with H. Stephen Glenn, Raising Self-Reliant Children in a Self-Indulgent World, says humor is a key tool to successful discipline. When moms or dads issue angry commands, kids of all ages tend to dig in their heels and resist. And no one benefits. How do you learn to take a lighter touch? Try these tips.