In a cross-cultural study of affection and aggression done at McDonald's playgrounds, pre-schoolers in France playfully touched each other twice as much US children did, but while the French children acted aggressively only 1 percent of the time, the US youth did so 29 percent of the time. Anthropologists have long known that cultures that shower physical affection on young children have little adult violence, dating back to Margaret Mead's studies in New Guinea. But the study in McDonald's playgrounds in France and the United States, along with other new evidence, suggests that it's time for America to take another...