I’m standing in the block aisle with my kids’ holiday wish lists. Usually, I’m there for my 9-year-old son. But this year, “Girl Legos” is carefully printed at the top of my 6-year-old daughter’s list.

As a mom of a boy and a girl – and a gender researcher who studies kids’ toys – I’m curious about this. Over the last five years, toy companies have begun to produce toys typically marketed to boys — like bow and arrows — in pink.

Is this a marketing ploy steeped in sexist stereotypes, or a brilliant way to encourage my daughter to want different kinds of toys — ones that help build, create, even engineer?

My colleagues and I turned to science to look into this possibility.

We bought two identical sets of traditional boys’ toys (think monster trucks and fighter jets). We kept one set blue, and painted the other set pink. Then we bought two sets of girls’ toys, like dolls and tea sets, and did the same.

We then allowed 73 preschool-age children to play with all four types of toys and rate how much they liked each one. The result? Boys preferred boys’ toys 20 percent more than the girls’ toys. And girls preferred girls’ toys over boys’ toys, though by just 5 percent.

But when boys’ toys were painted pink, girls liked them. In fact, girls liked them just as much as they liked those so-called girls’ toys. The only toys they were not interested in were the blue boys’ toys, which they rated 10 percent less interesting than all of the other toys.

Sadly, it doesn’t work the other way. Boys didn’t want to play with a tea set, whether it was blue or pink. The color blue doesn’t open the door for boys to play with all toys the way pink does for girls.

Why? It’s possible that the stigma against boys playing with tea sets and dolls is too strong to be overcome by simply changing toys’ colors. There is less pressure for girls to conform to gender norms than there is for boys, and girls are a little more flexible in what they consider to be “for them.”

In some ways, these results make me happy. The pink blocks appeal to my daughter in a way regular Legos don’t. And if she plays with them, I know it’ll help her learn math. Still, this pink-and-blue marketing strategy is trying to lure me into buying a pink set of Legos, when I already have a house filled with blue plastic blocks. Worse, it’s sending the message to kids that there are rules about what toys they should play with — and these rules are based on gender.

So for now, I’m going to pass on the “Girl Legos.” Instead, I’m going to pick up a big bucket of rainbow-colored blocks. This winter break, I hope you’ll find me at the kitchen table, building something together with my daughter and my son.