As social scientists, we think it's important to distinguish child-free individuals from those who are childless or not yet parents. People who are child-free make the conscious decision not to have kids. They're distinct from childless individuals – adults who want children but can't have them – and from people who plan to have children in the future.
In a recent study of 1,000 people, we found that over 1 in 4 Michigan adults did not want biological or adopted children and were, therefore, child-free. This number was much higher than those reported in the few past national studies that have attempted to identify child-free people, which placed the percentage between 2% and 9%.
Although we can't be sure why we identified more child-free people in our study, we suspect it may have something to do with how we determined who was child-free.
Past studies that attempted to estimate the prevalence of child-free individuals often focused only on women and have used criteria based on fertility. These studies left out men, older adults and biologically infertile people who nonetheless didn't want children.