I'm sure that if you've ever been to India or China (or Indonesia, or most of Africa) you'd probably be less quick to dismiss the idea.
That wasn't my point.
The whole study in this article is about industrial nations. The comparison didn't touch India or Angola.
It's neither about wealth alone - it's about education (own desk - time to learn etc. etc.) health and so on.
I've always had the idea that scandinavian nations are just a better place to bring up kids. There's more help organized in the neighborhoud either. The UK people tend to live apparrt from their neighbours. So do we germans.
Certainly that's not for every individual but that's the tendency.
How about your neighborhoud - are your kids been looked after by the neighbours time by time ?