On a faded-out orange paper from The Public Library Stockton -- San Joaquin County, California, Children's Services where my mom worked in the early 1970s:
"Why Tell Stories?
Every child is engaged in developing a concept of his own self. Since he does this by relating to his environment, it is easy to see that the materially deprived child may suffer. In an atmosphere of material affluence, the media oriented child of today is also often deprived.
Storytelling helps rescue the child from the dehumanizing effect of the machine age in which he lives. Hearing stories told provides an opportunity for the child to relax and savor the experience, to be enthralled, to be refreshed and enriched, to establish kinship with his past and with his peers, to dream dreams, to discover what is truth and what is sham, and to store up food for his spirit which will last all his life long."
There is no clear attribution, though there is a poem by Sara Teasdale just above it.