Do kids need well-defined rules before an incident occurs? Or should you impose one ("No biting," for instance) the moment they misbehave? What kinds of boundaries are appropriate, and how rigid should you be with little kids?
Martha Pieper, PH.D.: Health and safety rules are all that matter: You can't hurt anyone else, and you can't hurt yourself.
Dr. Neifert: Little kids are looking for consistent boundaries. They don't want too much liberty -- it's terrifying for a 2-year-old to think she's in control. They need physical boundaries, such as, "You can't cross the street by yourself or go into the baby's room when she naps." You can also set up rules that respect other people's rights -- you can't take toys or willfully damage someone else's things -- by the time your child is 2.
Lerner: Children aren't trying to be bad or to drive you crazy; they're usually just trying to explore. You always need to ask yourself, What is my child trying to learn, and how can I help her to do it in an acceptable way?
When a baby spills her drink, she's probably just trying to see what will happen when she drops it on the floor. So it's up to you to set limits. Just say, "You can't do your spilling here," and put her in the bathtub -- along with plastic bowls, spoons, and water -- where she can make a mess.
With a toddler, you can say things like "No hitting" to reinforce concepts. But it isn't until kids can logically connect events, when they are about 3, that they're developmentally able to understand limits. If your child hits a bat against a wall, you can say the rule is, "No bats in the house." Then take it away. The next time it is about to happen, she'll more likely be motivated to stop the action herself.
Dr. Sears: With little ones, distraction is an easier way to get the job done: "You may not play with a knife, but here's something else to play with." It's just common sense.