Another confounder is that parents with kids know what it's like to be single. Most people without children have no idea what it's like to have kids of their ow

Another confounder is that parents with kids know what it's like to be single. Most people without children have no idea what it's like to have kids of their own. There is a subset that knows exactly what it's like, and it's those who have lost their children. Ask them if they regret their choice. Or actually don't, because people in that situation almost never made it there by choice.