A certain amount of pushing, grabbing, and even punching is normal when young children get together. Most of the time it's nothing to worry about. Injuries are few; disputes are soon forgotten.
Coping Equals Aggression
Some toddlers and preschoolers, however, get into repeated and escalating tussles. For them, aggression becomes their main approach to coping with almost any situation. They are not bullies in fact, they sometimes seem to pick hopeless fights with children who are much larger and older than they are.
In some children this aggressiveness appears to be biological, and may even be present before birth. (Some of these aggressive children were seemingly restless fetuses who kicked more than the average.) As toddlers and preschoolers, their developing nervous systems do not seem to let them control their impulses as much as their age mates do. With others, it's more a matter of their needing to learn and practice social skills.
When Aggression Works
In other areas of their lives, aggressiveness is often rewarded. A child who cuts ahead of the line to go down the slide at the playground will likely get to use that slide the most. The one who acts up in preschool will probably get extra attention from the teacher. So being aggressive toward a playmate is but a small step to success. From a child's point of view, the difference between assertiveness and aggression may not be clear. Also, representations of aggressiveness in media often seem to be rewarded, so kids get a mixed message.
Spotting the Signs
The best way to handle an overly aggressive child is to prevent the behavior in the first place. Many of these children show a clear pattern to their behavior. They may be aggressive only at home or only in public. A child may be much more likely to be aggressive in the afternoon when he's tired, or when he’s feeling frustrated. This part of the pattern will help you be better prepared to intervene. Also, most aggressive children this age go through a consistent sequence of behaviors before they lash out with a punch or a kick. Some may clench their teeth and stare. Others may rock back and forth. It's a bit like watching a car rev up before it suddenly kicks into overdrive.
Helping Your Child
Once you've determined the most common triggers or timing, and can spot the escalating behaviors, the simplest thing to do is to remove the child from that environment even if it's only a few feet before he loses control. Take him away from the sandbox or the playgroup for a minute or two until he regains his composure and self-control. Once a child is out of control, he isn't able to do anything but fight and he isn't learning anything from the situation.
Greater structure also seems to help these children. With structure comes predictability, which helps them feel more calm and in control. Tempting as it may be at the time, spanking an aggressive child for his behavior does not work. In fact, it will probably makes matters worse since you're modeling the very behavior that you want him to stop.
As he grows older, odds are that the problem will go away. He'll have better verbal skills and more emotional maturity, both of which will help him when he's feeling upset.
Girls vs. Boys
While aggressive boys get more attention, girls get into fights too. Their aggression may be more verbal, even at this age. It may also be physical, but less obvious than a boy's punches and kicks. Like boys, aggressive girls need help learning better social and problem-solving skills.
Finally, remember that aggression is sometimes a sign of depression in young children. The underlying problem may have nothing to do with the person being hit or the situation that seems to trigger the aggressiveness. If your child seems uncharacteristically aggressive and isn't responding to your efforts to change things, talk to your health care provider about what's going on.