She didn’t want to have children. Turns out she was far from alone.

Amy Blackstone announced offhand at her nephew’s first birthday party when she was 29 years old that she didn’t want to have children. She had been thinking about it for a while but hadn’t said anything out loud before.

She and her husband had assumed, when they got married in their early 20s, that they would have kids, said Blackstone, who is now a professor of sociology at the University of Maine in Orono. But they kept putting it off. They checked in with each other every year and decided, no, not yet. By her mid-30s, she knew for certain. She just didn’t want kids.

She had also just applied for tenure, which would give her freedom to study what she wished. So she began to examine the growing trend of people deciding not to have children. In 2019, she published the book, “Childfree by Choice: The Movement Redefining Family and Creating a New Age of Independence.”

“I really wanted to understand what was wrong with me. Why do I not have this maternal instinct that everyone says exists in women? Why am I not drawn to having kids? That was the point at which I decided definitively, ‘No, I don’t want to have kids. But I also feel like I’m broken in some way, and I want to understand what’s wrong with me.’ Thankfully I learned, A, the maternal instinct is a myth, and, B, there are all kinds of people like me out there in the world,” Blackstone, now 52, said.

Like Blackstone, a growing share of adults in the United States say they are unlikely to ever have children, according to a study released Thursday by the Pew Research Center. When Pew surveyed adults younger than 50 without children in 2023, 47 percent said they were unlikely to ever have kids, up 10 percentage points from 2018.

The reasons? Similar to Blackstone, people younger than 50 tended to say they just didn’t want to. Women in particular were likely to give this reason — 64 percent versus 50 percent of men surveyed. Women were also more likely than men to cite negative experiences with their own families growing up.

Both women and men said they wanted to focus on other things, such as their career or personal interests; they couldn’t afford to have a child; or they were too concerned about the state of the world.

The downward trend should not be a surprise, Blackstone said. Fertility rates have been declining for decades , particularly after the Great Recession.

The U.S. fertility rate reached a historic low in 2023. Maine, which has a lower fertility rate than the nation, has also seen a continued decline in the number of babies born to women of childbearing age, according to March of Dimes. (Overall, deaths have outnumbered births in Maine since 2012. But, since 2019, more people have moved to Maine, resulting in an overall population increase .)

Pew surveyed both those under 50 and those ages 50 and older who don’t have children. About four in 10 of those in the older group said there was a time when they did want to have children. But it just didn’t happen for them.

Those in the older age group who didn’t have children were less likely to have ever been married, according to Pew. But, particularly among women, they were more likely to have an advanced education. Older women with no children tend to earn more than mothers. The opposite is true for older men: Those without children tend to earn less than fathers.

But majorities in both groups surveyed said not having kids has made it easier for them to save money and to have time for hobbies. Large shares of both groups said having a fulfilling life doesn’t have much to do with whether someone has children.

Blackstone was careful to make clear that she does not advocate for people not to have children. Rather she wants there to be a greater awareness about the need to consider parenthood thoughtfully.

Not having children is “a choice that we should be able to make with the support of our friends and family,” she said. Likewise, “we should be able to support people in their quest toward parenthood.”

In that way, the decline in people wanting to have children can be viewed in a positive light because women are having more agency over their lives, Blackstone said.

“We know that in areas of the world where women have access to education, where they have access to good medical care and where they have access to good jobs, fertility rates are much lower. So where women have agency, they tend to have fewer children,” Blackstone said.

However, there is a caveat: Research shows women in the U.S. are having fewer children than they’d like to.

“The things that hold them back include the belief that the future is not bright, a concern about the environment — both a concern about overpopulation and a concern about climate change,” Blackstone said. “The other thing we hear is that there’s a concern about a lack of social supports for parents.”

Research has shown that other industrialized countries tend to have happier parents. One 2016 study by Jennifer Glass, a sociology professor at the University of Texas at Austin, found that, of 22 industrialized countries, the happiness gap between parents and nonparents was widest in the U.S.

“We do know that the policies that support raising children do work in some regard. They certainly make parents happier. Whether they make people have more kids, I don’t know,” Blackstone said.