There's also the different family organization. My impression in Asia was that the elderly there spend a lot of time with their grandchildren, to the point wher

There's also the different family organization. My impression in Asia was that the elderly there spend a lot of time with their grandchildren, to the point where they cannot travel because they're on babysitting duty. Many people feel younger after playing with kids. I wouldn't be surprised if it also affects you on a more chemical level, for example by triggering different methylation and thereby changing gene expressions.