You don't know how it happened—but all of a sudden your sweet, obedient child has turned into a tiny tyrant, demanding this juice box, not that one, right now. Worse yet, his demands are arbitrary and contradictory—they change from minute to minute without rhyme or reason. This behavioral switch can be sudden, leaving parents bewildered.

"In the toddler's mind, it's their world and others are simply living in it", says Dr. Thomas McIntyre, professor at Hunter College of the City University of New York. "Very young children who are going through the terrible 2's (or 3's, or 4's) are very ego-centric—they can only understand their own needs and desires. They cannot yet comprehend that others might have requirements and wants as important as theirs."

Your toddler also displays a normal, healthy emerging individuality during these years. When your child says "no" or screams "I don't like that!" it's his way of saying to you that he's his own person—a necessary stage of development. But this can all add up to behaviors that parents interpret as difficult. So, how can you manage demands and tantrums, while setting limits for your child during these years? Should you attempt to reason with your little one, or is imposing more—and more severe—discipline the answer? Here are some helpful strategies:

  • Keep Your Cool. When your toddler has a meltdown, resist the urge to raise your voice over his shrieksi and sobs. If he gets loud, remain calm and quiet. He wants to know what your reaction will be to his behavior—he's testing your limits. If you speak in a soothing voice, your child may quiet down and listen to what you have to say.
  • Set Firm Guidelines. Don't be wary of imposing limits at the zoo or mall, out of fear that your rules may trigger a tantrum. Remind your toddler of "public place" rules, such as speaking at an appropriate level and not crying, before you leave the house. That way, if he begins a meltdown at the candy store, you'll be able to tell him that you're going home empty-handed because he didn't follow the pre-approved rules. Guidelines are especially important in unfamiliar situations, since toddlers get anxious if they don't know what's going on. If you are going to a new place—to a play date at an unfamiliar home, for example—set guidelines before you go and don't waver from them.
  • Be Consistent. Your child thrives on predictability in all aspects of his life—even discipline. If you tell him that he doesn't get ice cream for acting out, stick by your decision and skip giving him a sweet treat, even if he pleads and screams for it. Imposing the exact same consequences every time helps to reinforce simple and expected boundaries, which are the most easily digested and understood.
  • Keep it Simple. Dr. McIntyre points out that babies and toddlers have emerging language abilities and they often don't have the words to cope with a particular situation. A toddler in the midst of a tantrum cannot reason using adult language. If his bad bahavior prompts you to take away a toy, and that triggers a tantrum, don't try to explain why you're doing what you're doing right away. Wait until the screaming is over, and then give reasons for the punishment, using short sentences and simple words.
  • Repeat, Repeat, Repeat. Just because you have to say things over and over doesn't mean that your child isn't listening—it sometimes takes multiple repetitions and reinforcement for ideas to sink in. If you're grocery shopping with your child and he pulls something off the shelf, you may need to tell him that isn't allowed—even if you told him the very same thing the last time you were in the store. It may look like disobedience, but it isn't. Your toddler probably just forgot what you said last week.
  • Learn to Recognize Triggers. Once you learn to pinpoint events that spark unreasonable behavior, prepare yourself and your child before the situation arises. If bedtime regularly causes outbursts, start talking about going to sleep before it happens. Ask your child what story he'd like to hear, or which pajamas he wants to wear. Giving him choices around an emotionally-charged event can lessen stress.
  • Punish the Behavior, Not the Child. Choose consequences that matter, but never tell your toddler that he's bad—it's the behavior that's not acceptable. Punishments should be predictable and appropriate to the situation. When you can, decide how certain behaviors will be dealt with in advance. For example, your toddler should be told that he'll need to leave the park if he behaves poorly—he shouldn't be told that he's "too bad" to stay at the playground.
  • Follow Through. If your child won't get into the car, for example, don't tell him that you're "just going to leave him there." The first time you say it, he'll be scared—the second time, he won't believe you. Empty threats only aggravates unmanageable behavior.
  • Use Positive Language. Dr. McIntyre points out that toddlers say "no" a lot because it's a word that they are highly familiar with. Toddlers need a lot of attention, and it's easy for parents to get burned out and start simply telling their little one, "Stop doing that!" Ignoring negative behavior, and using positive language during good behavior—such as "Great job"—will reinforce your expectations in a constructive way.

If you're worried that your child is more defiant or irritable than normal, observe other children and talk to their parents. If necessary, consult your pediatrician and have your toddler evaluated.

It may take many consequences, limits and repetitions of the rules to reduce negative behavior—but you will see results. A study in the journal "Research in Nursing and Health" found that parents who were taught how to set limits and use positive reinforcement showed significant improvement in their relationships with their toddlers.

Above all, have patience—with smart management and consistent limit setting, you and your baby can successfully navigate the demanding years.