In Pamela Druckerman’s “Bringing Up Bébé,” the playground forms a fertile backdrop for her pop-sociological observations about child-rearing, French vs. American style. The upper-middle-class Manhattan moms (she can tell by the price of their handbags) follow their kids around the gated toddler playground narrating their activities. The French moms sit on the edge of the sandbox and chat with other adults. The Brooklyn dads follow their children down the slide. The French moms sit on a bench and chat with other adults. Her theory, a bestselling one, is that French parenting consists of more non, more équilibre, and thus more time for adults to be adults.