In play, the child creates a world into which she puts her thoughts, her imaginings and her feelings. The world she creates in free form is literally made out of herself, spun out of her own subjectivity. This created world, in turn, gives the child a sense of her self as an active, creative being. The child is the ruler of her tiny kingdom, and in it she feels deliciously free and alive
from:
How the Decline of Free Play May Have Caused a Decline in Sense of Control and in Intrinsic Goals, and a Rise in Anxiety and Depression
As I pointed out here and here—and as others have pointed out in recent popular books[5]—children’s freedom to play and explore on their own, independent of direct adult guidance and direction, has declined greatly in recent decades. Free play and exploration are, historically, the means by which children learn to solve their own problems, control their own lives, develop their own interests, and become competent in pursuit of their own interests. This has been the theme of many of my previous posts. (See, for example, the series of posts on “The Value of Play.”) In fact, play, by definition, is activity controlled and directed by the players; and play, by definition, is directed toward intrinsic rather than extrinsic goals
From:
Art for Social Action 