How many/what other cities does that include beyond Yokohama (which puts it around 16m)?

Also - The Bos-Wash Megalopolis is over 44 mil if you're going that way with it...

I believe that given there are tests available for Downs syndrome, people should be allowed to take them and given the option of termination (after counselling). However I would not take that option. I'm not sure if I would have the tests. I would like to be prepared if I were going to have a Downs child, but I would not want a test that would risk the life of the fetus. But that's just me -I am in a position where I could cope if I had to. Many many people are not.

However, if science advanced to the point where (say) people could be vaccinated against conceiving a Downs child, I'd be all in favour of that. It's wonderful that there are lovely people with Downs. They'd probably still be lovely without it... and they and their parents probably would have a better quality of life, even though that must be the hardest thing for families living with Downs to admit.

I got my info off Wiki. It's a college student's "Bible." Not sure about stretching Boston all the way to DC, Wiki just showed NYC-Newark as #3 largest agglomeration and Tokyo as #1.

BosWash wiki.

Dang. I guess it doesn't qualify.

Actually, in the industrialised West, the clustering of children into the early years of marriage only really began to happen around about the middle of the 20th Century (life/marriage patterns began to change from about 1870 onwards, certainly in England, but I believe in America as well). Prior to that the median age of women at the birth of their last child was about 39 and many of them continued having children into their forties. This obviously allows for extremes either side and must also take into account that in some areas of the country life expectancy was low by modern standards. Marriage age dropped considerably after the second world war, despite the fact that life expectancy had risen considerably (not sure if this also applied in the States, but was certainly the case over here). The fall in marriage age helped bring the median age of the mother at the birth of her last child to down to about 28.

You're right in that many medieval cultures considered young teens to be adult, but that changed centuries before the industrial age. You're also right that we are now moving into an era where the first child is tending to happen later, except for in those areas or communities we consider to be 'problematic'; but it isn't simply that as we live longer we spend more time in an infant state. The changes relate more to other external factors.

I don't know for sure that we can support a population twice the size it is now but we can support a population bigger than it is now if we really tried, those people being born in extreme poverty being the catch.

Well from a moral perspective this simply isn't acceptable. Why increase the number of people living in poverty?

Wouldn't it be better if the birthrate were controlled somewhat and population decreased so that no one needs to live in abject poverty?

From a view just looking at larger society, yes, definitely, but how do you enforce a one child policy without authoritarian control and taking away individual rights?

If you want to lower population growth without authoritarian control the ingredients are freedom, education, and wealth. But it is very unrealistic to spread those to every third world country with high population growth.

Just deny them access to medical treatment.

Then you just end up with this

How much medical treatment do you think they have access to?

Would I abort a fetus if I knew it had down syndrome. I don't think so. I truly do not believe so. So many of the kids that I coached at the Special Olympics would not have been "better off". That's crazy.
I can't wait for the day that we give an egg and sperm to the Dr. and you get your zygote engineered genetic disease free, and with the sex you want.
You can even pick your hair and eye color.
It is right around the corner.
Science is there to use.

Vincent Freeman, Gattaca

I'll stick with random chance, thank you.

Somehow this is just screaming dystopia...

When you can start actually picking traits as more preferable than others then the whole discrimination and supremacy thing will intensify again and that is never good. The getting your children disease free is always good though.