A friend of mine was bicycling through a quiet neighborhood one day last fall when, like a good citizen, she slowed to a halt at a stop sign. When my friend started pedaling again, a teenage girl who, flanked by a group of friends, was standing in the street near the corner as if she were going to cross, suddenly slugged my friend in the arm, knocking her off her bike and onto the ground.
At lunchtime recess on elementary school playgrounds, ball fields, and schoolyards across the nation, the joyful sounds of children at play are often interrupted by shouts of distress: "She took my basketball!" "He cut ahead of me!" "It's my turn!" "You cheated!" "Stop pushing!"