Interesting angle.<p>Childless people having more free time and less stress is pretty much a no-brainer, and I even wondered if those people would really regret not having children later on in life, but always thought that you can't miss what you never had.<p>But assuming your kids didn't end up as homeless drug addicts this sounds plausible.<p>I wonder though how this would change in different societies like China, where grandparents are frequently (ab)used as babysitters on a daily basis. They basically don't have much free time after retiring, and taking care of toddlers when you're in your early 60s sure doesn't get less stressful. Otoh not having children in China is very uncommon and in such a homogeneous society might come with just as much stress through social pressure...