Aggression in play. Adults may think that play is something that is fun and shouldn’t be taken seriously. Children often take it seriously. They may concentrate on something for quite a long time and practice it over and over again. Play is a developmental process for children and has important consequences for them. For example some activities may help to develop muscles and concentration while others may help develop social skills and to act towards each other. Aggression is something that is present in most children’s play in different levels. There are a number of definitions of aggression. Psychologists refer to, hostile aggression, which is aggression