The first step is to isolate. As I believe culture is the most likely culprit, I’d suggest isolating by culture. Compare murder rates in the US by Japanese first and second generation immigrants to murder rates in Japan. If similar, culture is likely a substantial culprit.
The first step is to isolate. As I believe culture is the most likely culprit, I’d suggest isolating by culture. Compare murder rates in the US by Japanese first and second generation immigrants to murder rates in Japan. If similar, culture is likely a substantial culprit.
If you wanted an even tighter test, check immigrants to different regions of the US, and possibly do two generations rather than just one.