Uh-oh. Here comes more bad news for the “gender is a social construct” crowd. 

A new study by researchers at the City University of London found that babies as young as 9 months old prefer to play with toys specific to their own gender. 

The experimenters, whose results were published in the journal Infant and Child Development this month, put 101 girls and boys between the ages of 9 and 32 months in a nursery with a variety of toys and observed which ones the children seemed to play with more. 

The toys used in the study were a doll, a pink teddy bear, a cooking pot, a car, a blue teddy, a digger and a ball. Toys were placed a few feet from the children so they would have to make some effort to get to them, and then researchers observed not only which ones they chose, but also how they played with them and for how long. 

Among the youngest, they found, the boys tended to prefer the ball and the girls wanted the pot. 

While modern parents like to think that everything is in our control when it comes to socializing children, the researchers found the opposite to be true. They write: “Our findings of sex differences in toy choice in the 9 to 17 months age group add some weight to the suggestion that such preferences appear prior to extensive socialization and do not depend on gender category knowledge but are reflections of our biological heritage.”

A recent photo series from a project called #ABoyCanToo has been going around on social media. It includes portraits of boys who pursue interests traditionally associated with girls. A Huffington Post article, “13 Empowering Photos Show There’s No ‘Right’ Way to Be a Boy,” says the pictures are “shining a light on kids who don’t let gender norms prevent them from following their dreams.” There’s a picture of a boy in a frilly lace dress and one dancing ballet and another with bows in his hair. 

But it’s not gender norms that are the biggest force at work here. Rather, it’s that boys are on average more inclined to play certain ways and girls are inclined to play other ways. Geula Zamist, the director of early childhood at a synagogue in New Jersey, recalls going to a museum gift shop with a friend many years ago. “I decided to buy all the children the same thing — a wooden recorder. By the time we got to the parking lot our 2-year-old boys were having a sword fight and our 4-year-old girls were giving a concert.” 

She says this is true in other instances as well. If you give boys and girls the same set of blocks, “boys will build tall towers and girls will build out flat.”

So is our gender divide in toys entirely the product of nature? Obviously not. 

In fact, the researchers observed that babies and toddlers made almost no distinction between the blue and the pink teddy bears they were offered. Which suggests that certain things, like the color of a toy, only matter once kids are socialized to certain ideas — namely that pink is for girls and blue is for boys. 

But if you take a walk down any toy aisle, it quickly becomes apparent how significant that point is. The girls’ toy aisle looks like someone dumped a giant bottle of Pepto Bismol on it. Girls want not only princess dolls and pink cooking sets, they also start to want pink versions of games like Chutes and Ladders and Trouble. 

If you look into preschool classrooms, which usually have plain toys — wooden kitchens, dolls without clothing, simple blocks — you’ll see boys and girls moving more freely among different areas. There’ll generally be more boys in the blocks and more girls in the kitchen, but there is no flashing (pink) sign warning boys to keep away from the girl toys. 

But so much of toy companies’ success is actually tied to TV shows and movies that it’s making the divisions that are present naturally much more pronounced. Hasbro, which released its earnings last week, saw a 15 percent jump in what the company calls Partner Brand revenues — “Star Wars” for boys, Disney princesses for girls. 

If you want to “empower” your children, as the gender-norm warriors like to say, don’t take away your daughter’s dolls and give them trucks or demand your son stop using crayons as weapons. Instead, send kids to play outside more — girls and boys like to ride bicycles and play on swing sets — or buy them toys that aren’t tied to the latest movies or TV shows. 

However impossible it seems, it may mean doing more to separate our children from popular culture.

Naomi Schaefer Riley is a senior fellow at the Independent Women’s Forum.