When children are together, they develop their own rituals, traditions, games, and legends—essentially, their own folklore, or, as researchers call it, “childlore.” That lore can be widespread and long-lasting—the mind boggles to think how many generations of children have played tag, for instance.

This sacred communal knowledge, along with other ephemera of youth—the blueprints for a cootie catcher, the words to a jump-rope rhyme, the rhythm of a clapping game—is central to the experie

nce of being a kid."