Play is especially beneficial to children's learning when it reaches a certain degree of sophistication. In other words, “unproductive” play happens not only when children fight and argue over who is going to be the “mommy” and who is going to be the “baby,” but also when the child who is “mommy” keeps performing the same routines with her “baby” day after day with no change. By contrast, play that has a potential for fostering many areas of young children's development, including social and cognitive development, has the following characteristics: