Suppose we try to organize those countries in the table that Jophiel links to. The lowest ages of first sex are these countries, where it’s between 15.6 and 16.5. I guess we would call them the Nordic countries. We can’t call them the Scandinavian countries, since they don’t speak a Scandinavian language in Finland:
Finland 16.5
Norway 16.5
Sweden 16.2
Denmark 16.1
Iceland 15.6
The next group are a group of mostly European countries (in none of which is the main language English), where it’s between 16.7 and 17.8. It includes Brazil and Chile from South American though. Since the list doesn’t include other South American counties, it’s hard to tell what the average is there. It includes Israel, but my impression is that Israel feels culturally more European than Middle Eastern. The list doesn’t include other Middle Eastern countries, so it’s hard to tell what the average is there:
Slovakia 17.8
Germany 17.6
Brazil 17.4
Ireland 17.3
Croatia 17.3
Austria 17.3
Czech Republic 17.2
Chile 17.2
Belgium 17.2
Portugal 16.9
Bulgaria 16.9
Israel 16.7
The next group are the English-speaking countries of the world, plus four other European countries (France, Switzerland, Greece, and Turkey), where the average is between 17.8 and 18.7.
South Africa 18.7
France 18.5
United Kingdom 18.3
Switzerland 18.2
Canada 18.1
Netherlands 18.1
Greece 18.1
United States 18
Australia 17.9
Turkey 17.8
New Zealand 17.8
The next group are some more non-English-speaking European countries, plus Indonesia, Taiwan, and Mexico, where the average is between 18.7 and 19.2.
Spain 19.2
Indonesia 19.1
Poland 19
Italy 18.9
Taiwan 18.9
Russia 18.7
Mexico 18.7
The rest are Asian and African countries (although it’s the only African country the list includes), where the average is between 19.4 and 23:
Malaysia 23
India 22.9
Singapore 22.8
China 22.1
Thailand 20.5
Hong Kong 20.2
Vietnam 19.7
Nigeria 19.7
Japan 19.4
So it’s Nordic countries < a mostly European group of countries with a little lower ages of first sex < a group of English-speaking countries and some other European countries < a mostly European group of countries with a little higher ages of first sex < Asian (and maybe African) countries. I suspect that there’s some way to characterize each group more by culture than by location, but maybe someone else here can do that. Also, let’s note that these are not huge differences. Globalization has pulled the world together in this just as in many things.