Almost 20 percent of American women end up going childfree, according to a new report by the Pew Research Center. In 2008, 18 percent of women reached ages 40 to 44 without having borne a child, compared to just 10 percent in 1976.

“The fact that nearly one of five women does not have a child of her own — that’s an enormous transformation from the past,” Pew researcher D’Vera Cohn told The Washington Post.

About half of these women are childfree by choice. So, is society becoming more accepting of that choice?

Yes, write Cohn and co-researcher Gretchen Livingston:

Over the past few decades, public attitudes toward childlessness have become more accepting. Most adults disagree that people without children “lead empty lives,” a share that rose to 59% in 2002 from 39% in 1988, according to the General Social Survey. In addition, children increasingly are seen as less central to a good marriage. In a 2007 Pew Research Center survey, 41% of adults said that children are very important for a successful marriage, a decline from 65% who said so in 1990. … Scholars say that social pressure to bear children appears to have diminished for women and that today the decision to have a child is seen as an individual choice. Improved job opportunities and contraceptive methods help create alternatives for women who choose not to have children.

But some prejudice persists and is even worsening:

As for the impact on society, attitudes are more mixed. About half the public — 46% in a 2009 Pew Research Center poll [PDF] — say it makes no difference one way or the other that a growing share of women do not ever have children. Still, a notable share of Americans — 38% in that 2009 survey — say this trend is bad for society, an increase from 29% in a 2007 Pew Research survey.

A childfree lifestyle is more common among white women than other races, though black, Hispanic, and Asian women are catching up.

The most educated women still are among the most likely never to have had a child. But in a notable exception to the overall rising trend, in 2008, 24% of women ages 40-44 with a master’s, doctoral or professional degree had not had children, a decline from 31% in 1994.

A childfree life doesn’t have to be a bummer, The Washington Post helpfully points out:

Childless women are as happy as women who had children at typical ages, said Amy Pienta, a researcher at the University of Michigan who coauthored a study on the subject. “They are not any more depressed; their psychological well-being is just as high,” she said.

I could have told you that. And — bonus — our carbon footprints are lower too.

All in all, this report is good news — women are more free to choose how they want to live their lives, and, to the extent more of us are choosing not to have kids, the environment benefits in the process.

Read more about population and the childfree option: