When two boys start play-wrestling in public, things can get ugly.
Recently, Stephanie Maingot watched with an eagle eye as her six-year-old son grappled with a young heavyweight at a kids' play centre in North Vancouver.
The other boy's father ignored the scene, she says, even after his son started slamming her child onto the mat. Then, just as she was about to intervene, her son socked his opponent in the eye.
Mortified, she rushed to the boy's side and walked her son through an apology. But the boy's father had no patience for social niceties, she says.
"He told his son, 'You're bigger than him - you could have kicked his ass!' "
At that point, Ms. Maingot realized that making amends was futile, she says. "I backed off because I knew our values were different."
So much for the lesson in conflict resolution.
In urban settings with few social norms, kids' play areas have become minefields, parents say.
There's no code of conduct for physically separating someone else's child in a fray, or dealing with other parents when their kids cross the line.
And contrary to the adage, "it takes a village to raise a child," today's parents are territorial about their kids.
A generation ago, when authoritarian parenting was the norm, any adult was entitled to reprimand a misbehaving child, says Judy Arnall, a Calgary-based parent educator.
But the etiquette has changed, she says.
"It seems almost not polite now to speak to other peoples' kids," she says. "I think parents are really scared to get chewed out by other parents."
Adults can be especially touchy about physical contact with their children, Ms. Maingot says.
She recalls a time at a mall when a boy backed her son in a corner and started spitting at him. When she gently placed a hand on the boy's shoulder and asked him to stop, his grandmother "came out of nowhere and just started screaming at me," she says.
The growing diversity in parenting styles - from neglectful to permissive to draconian - has added to the confusion about discipline, Ms. Arnall says. Some parents let their kids fend for themselves while others try to micromanage the play area.
Mothers of docile girls often overact to aggression in the playground, Ms. Maingot says. "They tend to have zero tolerance for what I would consider to be normal behaviour, which is ritualistic play-fighting."
Biting, shoving and sand-throwing are everyday events at playgrounds, especially among toddlers who haven't learned self-control.
But in heavily used kids' facilities, adults lose it too.
Margaret Buxton was looking after four children at Science World in Vancouver when a dad went ballistic, she says. His daughter was in a wheelchair race against her son while the other kids cheered him on. Angry that his daughter was losing, the father threatened to slap one of the children in her care, Ms. Buxton says.
The menacing words roused her inner Mama Bear. "I told him, 'If you slap my kid, I'll break your face,' " she says, adding that she and her wards made a quick exit.
When parents behave badly, "the best thing to do is just back off," Ms. Arnall says.
She describes an incident in which her seven-year-old son threw a ball at another kid in a play area at a McDonald's restaurant in Calgary. The boy's father ordered her son to come out and "face this like a man," she says. Then the father started yelling at her.
Ms. Arnall saw no point in fighting back, she says, but if the situation had escalated, "I would have called the police."
Nevertheless, in most cases, adults can turn sandbox skirmishes into learning opportunities, she says.
Parents can teach children as young as 2 to practise setting boundaries using words such as "I don't like being pushed."
The next step is for the parent to approach the aggressor and say something like, "please don't push people," she says. The key is to be polite, "because you're modelling for your child."
A parent should only notify the child's caregiver if the misbehaviour continues, she says. A reasonable parent will say, "Oh thank you, I didn't notice."
Children benefit from receiving gentle discipline from a range of adults in their lives, Ms. Arnall points out.
Even so, many parents say they're reluctant to deal with other people's kids, no matter how politely.
"I don't believe it's my role to disciple another child," says Anita Zaenker, a Vancouver mother of two boys.
When a child is causing problems for others, she says, she brings the matter to the other caregiver's attention so he or she can communicate with the child as the adult sees fit.
Ms. Zaenker says she has learned from playground experiences that "some guardians don't like other adults talking to their children."
If the guardian is nowhere to be found, Ms. Zaenker tends to remove her kids from the situation, she says, adding that the potential for conflict at kiddie parks can be exhausting.
"Some days it's easier to avoid the playground altogether."