“No pants, Mommy,” Rachel proclaimed. “Dwess.”

I’m not one of those moms who dreamed giddily of having a little girl I could adorn with ribbons and eyelet-trimmed frocks. On the contrary, my daughter often wore hand-me-downs from her brother. I was being thrifty, eco-conscious, and resisting gender stereotypes. It was a parental trifecta.

I’d heard from other moms that it wouldn’t last, that my daughter would awake one morning captivated by princesses or baby dolls, and my little experiment would be over. And, indeed, I knew something was afoot one day when Rachel grabbed my hand and observed, “Two girls walking down the stairs.”

We were alike, she and I. We were girls, not boys.

So began the cascade. The dress-only edict. The Cinderella pull-up diapers. I found myself almost embracing it, checking eBay for yet another flowered Hanna Andersson dress, buying sparkly shoes at Sears.

What had happened? Was Rachel genetically programmed to be a girlie girl, a wee diva?

More likely, she’s deciding who she wants to be, says Ellen Hanson, a clinical psychologist at Children’s Hospital Boston. Between the ages of 2 and 4, children have so much going on mentally: They’re defining themselves, beginning to understand the differences between men and women. Implicitly or explicitly, children get support for exhibiting behaviors that hew to cultural norms. When a little girl wears a dress, we might tell her how pretty she looks. If she carries a baby doll or pretends to be a princess, well, she’ll find herself in good company.

“They’re just trying to find their place in the world,” Hanson says. “And parents aren’t fully in control of that.”

That much is clear. These days, even in a dress, Rachel’s wearing the pants in the family.

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