Here is an interesting excerpt on the impact of stories in a child's growth by Joseph Campbell in his book, The Hero's journey.
"It is from innocent children that I learned what happens when a young soul is held away from the breadth and meaningful nuances of stories for too long. Little ones come to earth with a panoramic ability to hold in mind and heart literally thousands of ideas and images. The family and culture around them is supposed to place in those open channels the most beautiful, useful, deep and truthful, creative and spiritual ideas we know. But very many young ones nowadays are exposed almost exclusively to endless "crash and bash" cartoons and "smack 'em down" computer games devoid of any other thematic components. These fragmentary subjects offer the child no extensive depth of storyline.
When I have taught children as an artist-in-residence in the schools, I have found that many children were already starved for deep story before they had reached second grade. They tended to know only those from sit-com television, and they often reduced their writings to these drastically narrowed themes: "A man killed another man." "He killed him again and again. Period." "They lived, they died. The end." Nothing more.
One fine way parents, teachers, and others who cherish the minds of the young can rebalance and educate modern children's psyches is to tell them, show them, and involve them in deeper stories, on a regular basis. They can also begin to interpret daily life in mythic story terms, pointing out motifs, characters, motives, perils, and the methods of finding one's way. By these means and more, the helpers override the immense repetition of one-point-only stories that so much contemporary media and culture so harp on ad infinitum. The mythic is as needed as air and water. The mythic themes not only teach, but also nourish and, especially, energize the psyche. The vast world of story is where the child's spirit will find these most consistently. The radical knowledge and amazements found in stories ought to be every child's daily inheritance."You can buy the book here.