Thing is, I totally randomly met a British criminologist while visiting Svalbard a few years ago and I spent a while talking to him. He generally agrees that homogeneity reduces problems in a society. If everyone's the same, everyone kind of gets along. There is merit to that argument for better or worse, although I believe we can also move past that in time.

Regarding incarceration rates specifically, the next 3 leading jailers behind the US (Russia, the Ukraine and Poland) are unbelievably homogeneous. I believe Poland is almost 97% white [1]. They're my people, so I think I can safely say, they consider a mild tan to represent diversity. There are homogenous countries that lock people up, and there are homogenous countries that don't. There are also diverse countries that lock people up, and diverse countries that don't.

I was trying to be very careful in not comparing Norway's incarceration rate (which is, itself, 1/10th of the US) but rather their substantially lower recidivism rate which I think one can more easily treat as an apples-to-apples comparison, meaning that there is room to improve on the process.

[1] https://www.chicagotribune.com/news/ct-xpm-2005-10-16-051015...