A dull book seeking to prove that the Tooth Fairy, the Easter Bunny, and Santa Claus are myths beneficial to children's development. Trained in anthropology and developmental psychology, Clark interviewed 133 children and 72 mothers in order to evaluate the benefits and drawbacks of children's faith in nonexistent beings. Her opponents are an unlikely pairing: social scientists who believe that lying to children undermines the essential trust between parent and child, and Christian fundamentalists who wish to preserve the religious significance of Christmas and Easter. In her briefest and most convincing discussion, Clark argues that Tooth Fairy rituals ease children through the difficult process of losing their primary teeth. Santa Claus and the Easter Bunny get lengthier and more confusing treatment. Clark believes that these characters encourage the imagination and that children freely introduce personal elements into the holiday rituals surrounding them. ``This active influence of the child on festival observation directly contradicts expressed views of many social scientists who espouse a more passive view of `socialization,' '' she states--yet the examples she cites are of two children who learned about the holiday observance in their parochial schools and of one non- Christian six-year-old who told her mother that they had to prepare for Easter because all the neighbors were. In light of how adults perpetuate such beliefs in children, it seems odd to insist that children's experience ``has just as much validity...as the faith and experience of adults,'' nor is it clear why Clark excludes fathers from her study. Interesting questions about when and how children are disabused of their beliefs are touched on only briefly here, and then mainly in the case of a born-again Christian. At best, glaringly inconclusive. At worst, sketchy and poorly analyzed.