Last summer, researchers at Michigan State University reported that one in five Michigan adults, or about 1.7 million people, don’t want children and therefore are child-free. Although that number was surprisingly large to many data has now been confirmed in a follow-up study.

“We found that 20.9% of adults in Michigan do not want children, which closely matches our earlier estimate of 21.6%, and means that over 1.6 million people in Michigan are child-free,” said Jennifer Watling Neal, MSU professor of psychology and co-author of the study. “Michigan is demographically similar to the United States as a whole, so this could mean 50 million to 60 million Americans are child-free.”

The new study published in PLOS ONE attempted to replicate the original study by using the same methods, but with a new sample of people. The researchers used data from a representative sample of 1,000 adults who completed MSU’s State of the State Survey, conducted by the university’s Institute for Public Policy and Social Research. To avoid any risk of cherry-picking results, the researchers preregistered the study by recording in advance exactly how the study would be conducted and what they expected to find.

“Many adults are child-free, and there do not seem to be differences by age, education or income,” said Zachary Neal, associate professor of psychology at MSU and co-author of the study. “However, being child-free is somewhat more common among adults who identify as male, white or who have always been single.”

Some express concern that child-free adults will regret the decision not to have children, especially later in life. But Watling Neal explained “we found no evidence that older child-free adults experience any more life regret than older parents. In fact, older parents were slightly more likely to want to change something about their life.”

Because so many people are child-free, the researchers said this group warrants more attention, particularly as reproductive rights are being eroded.

“States’ restrictions on reproductive health care may result in many people being forced to have children despite not wanting them, which is very concerning,” Neal said.

The research team is now examining whether abortion restrictions affect adults’ choice to be child-free and are expanding their work beyond Michigan to include other states and countries.