Rough-and-tumble play is when children wrestle, roll, hit, and run after each other (Berk, 2010). It helps to self-regulate aggressive behavior with young children. Boys like to wrestle and hit while girls tend to chase with little physical contact. According to Berk (2010), “dominance hierarchy—a stable ordering of group members that predicts who will win when conflict arises.” There is a hierarchy that is decided by the child assessing their opponent before challenging. Rough play declines when the child gets older and there is less aggression due to self-regulation and dominance hierarchy.