Three-year-old Tommy likes to dress up as Cinderella.

Four-year-old Sally barely glances at the dolls in her room. She favors toy trucks.

Five-year-old Joey doesn’t want to play sports. He’d rather play house.

Should their parents be concerned?

No, say the experts. That’s what play is all about.

“Pretending to be the opposite sex is not a sign of gender confusion,” says Dr. Pete Stavinoha, a neuropsychologist at Children’s Medical Center. “It’s more likely to be a part of the process of finding their identity by trying on different qualities represented by the roles they play.”

And “trying on” includes not only costumes but also attitudes and behaviors. It’s common for preschoolers to switch back and forth between roughhousing “boy stuff” and sugar-and-spice “girl stuff.” As gender identity develops through early childhood, this is an expected phase of healthy, even necessary, exploration, no matter how puzzling it might be for parents. And it doesn’t have to indicate anything other than a natural desire to experiment.

So you should support a child’s desire or willingness to challenge gender stereotypes. “While disapproval is likely to undermine self-confidence,” says Dr. Stavinoha, “accepting and supporting it will contribute to a sense of pride.”

In recent years, the lines between male and female roles have blurred to some degree. But those lines still exist. Kids learn what it means to be a boy or a girl from their environment, their playmates and especially their role-model parents.

So parents usually are advised to let children pursue their interests without being confined by gender stereotypes.

A child shouldn’t have to choose between gender and natural inclination. The goal should be to raise sons and daughters who are secure in their gender without feeling restricted by it.

“Remember,” says Dr. Stavinoha, “this is only play.”