When a young child has self-control, she can be counted on to keep unruly impulses in check and to behave in a "grown-up" manner. Gaining this capacity is one of the most important tasks of early childhood, and parents are integrally involved at every step along the way.

By age 2 children are actively exploring their environment. While this represents an important advance in the quest for autonomy, a child's newfound curiosity also subjects him to potential safety hazards. As a result, parents often find themselves exerting enormous controls on their children to keep them safe: They run after them on the street or stop them from climbing too high on playground equipment.

The parents of a 2-year-old must restrain her actions because she doesn't yet have the physiological capacities or the judgment to do so herself. For instance, if a child runs full speed toward a wall, she simply doesn't have the muscular coordination to stop quickly enough to avoid injury. She doesn't even have the capacity to understand the dangers of not stopping.

But simply saying no or don't to an out-of-control child may bring on a temper tantrum. As every parent knows, even the most reasonable child will sometimes insist on doing just the opposite of what his parent expects, especially when it involves issues of physical autonomy like eating and toilet teaching. A child often can't exert self-control as emotions escalate, but a parent can. The parent should stop, pull back, and make sure she's not expecting something the child cannot do at that moment.

Between the ages of 3 and 4 a child's physical and cognitive skills begin to improve, and parents no longer exert total control over his actions. Because the child's neuromuscular system is more mature, it is easier for him to make his body do what he wants it to do. And because his depth perception has developed, he is now more able to assess whether there's a danger of falling when he's playing on furniture or climbing equipment.

Moreover, the child's increasing cognitive capacities make it easier for him to understand cause and effect. For example, he now knows that if he crosses the street without looking, he could get hit by a car. He realizes that if he drops his mother's vase, it will break. Realizing the possible consequences of his actions makes it easier for him to resist the urge to act impulsively. By the age of 4 or so the child is far better able to take charge of his behavior. He has a strong desire to please his parents, which is combined with a wish to avoid punishment.

One of the best ways parents can reinforce their child's increasingly positive behaviors is to try to set an example of self-control. It's easier for a child to learn to restrain his impulses if he sees his parents doing the same. With his parent's support and understanding, a preschooler can develop the skills that make learning self-control possible.

Praise your child when he makes a special effort to control his impulses. Saying something like, "I'm glad you asked me before you climbed high up on the jungle gym," not only reinforces your child's good judgment but shows how much you value the behavior.