See School Ditches Rules and Loses Bullies. Here are some excerpts from this article:
"Ripping up the playground rulebook is having incredible effects on children at an Auckland school.
Chaos may reign at Swanson Primary School with children climbing trees, riding skateboards and playing bullrush during playtime, but surprisingly the students don’t cause bedlam, the principal says.
The school is actually seeing a drop in bullying, serious injuries and vandalism, while concentration levels in class are increasing."