I'll be honest, my eldest is almost two and I haven't seen aggressive behavior in her but she plays with some older kids in our neighborhood in this age range. One mother (who I adore and totally respect) pulled her son aside after an aggressive interaction and asked him if he knew why she was pulling him aside-- he said no-- she simply explained that he couldn't play like that because it wasn't nice. She told me that he's acted that way before and her advice was to just catch that behavior in the act or soon after so that your child knows exactly what it was that he or she did that isn't OK.

When I notice aggressive behavior with kids in my classroom I immediately remove them from the situation. Whether it means stepping outside or going into a quiet area in the classroom. I use short simple sentences and tell the child that it is never okay to hurt someone. That all children need to feel safe when they come to school. I help role model another way to deal with frustaton and anger also.