Don't Asians tend to live longer and have better health in general?

I don't know if it's due to something genetic, or because of something Japanese people do after they're born.

FWIW, Asian Americans in USA also tend to live longer than other ethic groups.

Now that I think about it, I realise USA might be a good natural setting to study these kinds of differences because there's a lot of people from a lot of places over there, unlike other countries where the population is more homogenous. Or maybe I'm wrong (I'm not from USA, but when I visited there I was astonished by the number of people from all over the world who were there).

Apart from the extremes of heteromorphic differences that can occur between different populations of humans, and the small chance that a very small woman might give birth to a very large baby.. What does any of that have concretely to do with society being Homogenous? What evidence do you have that Japan is actually Homogenous? How do you define that.. There is great diversity in Japan...

I wish 97.8% monoculture was considered diversity. My conglomerate can't get any cash from blackrock unless we're at least 65% diverse and make our advertisements about ESG instead of the product we're selling.

I thought the birth rate was very low? Did I get that wrong?

Birth rates isn't the right word. Neonatal mortality

No, you’re right. Im assuming they mean child mortality.