Q: I take my 6-year-old daughter to the playground a lot after school, and I've noticed a weird phenomenon: The girls tend to get together in packs and single out a boy to chase around. The boy's always laughing and seems to enjoy it, but I'm curious as to why this happens at this age.

A: According to Stanley Greenspan, coauthor of The Challenging Child, children at this age move from being family-oriented to being peer-oriented. One way they explore their relationships with their friends and their position in the group is through play.

Playground chasing is about exploring friendship, says Sharon Gesse, a child-life specialist at Children's Hospital of Michigan, and it's a primitive form of flirtation. Once they get to school age, girls begin to gather in small cliques—and chasing boys is an activity that solidifies their standing as part of the "in" crowd. "This is a common way to be part of the group while satisfying their curiosity about boys," says Marilyn Segal, dean emeritus at the Family and School Center at Nova Southeastern University in Fort Lauderdale.

Donna Pylman, a mother of three in Irvington, New York, witnessed that behavior when her daughter Marissa was in kindergarten and first grade. "She and her friend used to chase one of the boys because the friend liked him," she says. Now that Marissa is 10, the dynamics of the playground have changed. The boys usually play soccer at recess and the girls either join them or play amongst themselves.

School is the place where many children explore the sides of their personality that they keep in check at home. They also tend to develop different kinds of relationships. "Isabel plays with girlfriends outside of school," says her Mom, Susan Abraham of Montclair, New Jersey. "At school, her aggressive side and tendency to push the limits come out. Chasing boys is one expression of that."

If you're on the playground and see the game begin, you may want to keep an eye out to make sure nothing inappropriate occurs. Unless the boy who is being pursued is upset or uncomfortable by the attention, or the game becomes too physical and you are worried about someone getting hurt, avoid interfering.

Liza Asher is a mother of four and writes on parenting issues for national magazines. She lives in Montclair, New Jersey.