Maintain a positive relationship with the child. A child that is close to you will take notice when his behavior upsets you.
Determine the cause behind the child's distress. Knowing whether her aggression is caused by frustrated desires or interpersonal conflicts will help you prevent a repetition of similar problems. It also offers you the opportunity to teach her how to manage her feelings in similar situations.
Predict potential aggression triggers in the child. If, for example, hunger, fatigue or difficulty sharing lead to a child acting out, make sure he is well fed, well rested and has access to his own toys. Also, help the child to understand the importance of sharing and how to manage his feelings when things aren't going right.
Remove the child from impossible situations. For example, a 3-year-old child raised in a quiet and calm home with no other children may be ill-equipped to handle a busy, frenetic preschool classroom. She might fare better if given another year to prepare and develop at home.
Discuss aggression with the child. She might not understand that lashing out physically at other people or objects is both undesirable and dangerous. While you cannot have a philosophical discussion with most preschoolers about the personal and social benefits of being calm and self-possessed, you can point out to her the nature of actions and consequences. This reinforces her understanding when potential triggering situations arise.
Reward the child's good behavior. Positive reinforcement is a powerful tool. When a child learns that if he is calm, he earns a treat, a toy or a desired activity, the child will have more motivation to manage his own emotions and overcome the impulse to be aggressive.