My 14-month-old grand- daughter sits on the floor tenderly rocking her milk bottle back and forth in her arms.

“Hmm, maybe she needs a doll?” I say, quietly wondering if such a Christmas gift would be gender stereotyping her too early.

“Of course she needs a doll,” retorts my daughter, the toddler’s mom, in a practical, post-feminist voice.

Suddenly, I am remembering my attempts at the progressive upbringing of said daughter and her brother in the 1970s.

When Scott was about 6, I gave him a book called “William’s Doll,” then was guiltily relieved when he totally ignored it. (Would liking dolls, or even doll books, mean he would turn out to be gay?)

But when Heather at age 2 played with her older brother’s racecar track as much as he did, I was overjoyed.

So did my attitude, perhaps unconscious, about what each would choose govern their choice of play activities? Or did my attitude even matter?

Recent brain experiments have revealed that the biggest gender differentiation in 3-year-olds is that, across human cultures, boys will quickly choose a toy gun and a girl will choose a doll. This is the age they are forming their gender identity with intensity and purpose.

“Toy preferences almost certainly have an innate basis … . One clue is that male monkeys prefer to play with trucks while females prefer dolls,” write neuroscientists Sandra Aamodt and Sam Wang in their 2011 book, “Welcome to Your Child’s Brain.”

Of course, culture and parental attitudes have an influence. But only to a degree, and usually later on in the child’s life when he or she is secure enough in his or her gender identity to branch out.

Denver Waldorf School educator Nancy Blanning, who has worked with young children ages 3 to 7 for more than 30 years, says that the big question is, “How can we offer experiences that both temper and enhance the child’s natural choices?”

For example, at Waldorf, both boys and girls have been given cloth dolls that they will turn to at naptime, but often in differing ways. Last week, for example, two of the boys attached their dolls to broom handles and began swinging them around. “We see that, whatever the toy, boys need to move things and to build things,” Blanning said.

As a feminist, I am appalled at the gross vengeance with which stores have recently returned to promoting toys by gender. But in the long term, I’m not sure this “super sexist marketing” makes much difference.

So here’s my message to parents (especially moms) who worry about the daughter who only “thinks pink” at the age of 3: Relax! Given broader opportunities, she will most likely grow out of it. And if she still likes all things pink at the age of 20, that’s OK, too.

And to parents (especially dads), here’s a more crucial message: “It is true that about half of the boys who prefer girl toys do grow up to be gay — and also true that many of them do not,” write Aamodt and Wang.

“Playing with girl toys and adult homosexuality both result from earlier influences on some boys’ brains, perhaps due to prenatal experiences or genetics,” they wrote. “By the time you can observe the behavior, the outcome is out of your control, so you might as well get comfortable with it.”

Yes, I did give my granddaughter a soft, snuggly doll named Buttercup for Christmas. Delighted, she immediately cuddled it to her neck and took it to bed for her nap.

But later, she watched her older brothers’ new, remote- controlled “terrain twisters” bumping and colliding, accompanied by their screams and laughter.

Then, thwapp! Throwing Buttercup against the wall, she scrambled toward the action.

Dottie Lamm, former first lady of Colorado, is a psychiatric social worker and political activist.