Eliot Peitso of Charlestown, Massachusetts, was desperate to get outside. Or so he said. "Out! Out!" he yelled. His mom, Jennifer Johnson, rushed to get ready. Diaper bag packed, house keys located, toys and snacks stuffed into the stroller, she opened the door and had just stepped out when, suddenly, 20-month-old Eliot burst into tears and demanded to stay inside. Did he change his mind? Not exactly. Crossing the threshold again, Eliot wailed louder: "Out! Out!"

"So there I was," Johnson says, "bringing him back in, taking him out again -- which drove us both crazy!" Surely Eliot didn't want to spend the morning stuck in a doorway. In fact, after his mom finally got him out of the house, with tears streaming down his face, he began bouncing up and down in excitement only a block later.

Kids are a bundle of contradictory impulses. Adults are, too, sometimes: "I am so not hungry for dessert," we may say, even as our fork is poised to spear a generous bite of cherry pie. But why do children so often say the exact opposite not only of what they mean but of what they want or need? A little boy, his legs twisted more tightly than a braided loaf of challah bread, insists "I don't need to go!'"

A little girl who could talk of nothing else but her best friend's birthday party awakens that morning and announces: "Parties are dumb. I'm staying home!"

"Our kids aren't out to get us," says Mary Sheedy Kurcinka, author of Kids, Parents, and Power Struggles: Winning for a Lifetime. "Paradoxical behavior like this often happens because a child's feelings are in conflict with his needs, but he hasn't learned how to express either yet. Our job is to figure out what those feelings and needs really are and to help our kids voice them." The most common ways children sabotage themselves, and how we can help: