I think the cream of the crop in India gets the fuck out of that country and colonize Western countries. It is a population based study, and there is a lot of poverty and uneducated in India. The smart are incredibly bright; go to any medical school or Ivy League school. However, the poor are not smart or too uneducated to know better.
I am shocked that Canadians are higher than the US. Every Canadian I have met was a complete dipshit.
The Canadian public education system is on a way higher level than the American public education system up until the university level, and then its debatable. I'm talking about averages in public schools, not private or affluent area public schools. In Canada, even the poorest of areas have decent education. The same can't be said for ghetto schools in the States, where its basically a grown-up kindergarten.
When it comes to university education, then there can be debate, since the US has all the Ivy schools and Canada has none. Canada has a few well known and respected universities, but the US has a lot more.
If your argument is about "natural intelligence" (or street smarts) then clearly you've met some dumb-ass Canadians, and that's not really a representative of the whole population. Just like saying that all Americans are bad at global geography, as is the stereotype.