The US does not have the highest incarceration rate in the world: https://en.m.wikipedia.org/wiki/List_of_countries_by_incarceration_rate
It's 4th, and the difference between the US and the next few dozen isn't that significant.
Also, you are assuming cause and effect. The US is a rich, well developed country with an unusually high black population due to slavery. The much simpler explanation is that the black population are much more criminally inclined. The fact that their average IQ is significantly less is explanation enough: criminality is closely tied to IQ.
There is certainly a lack of peer reviewed papers to proof your point. I hope you know that IQ is also a defined test one can improve results by training for it. It is nothing genetically fixed in the IQ-test.
When I did ask Claude for high correlations of crime and murders, then claude lists the following:
Sorry I always have a problem uploading fotos.
Claude answered:
Key socionomic factors correlated with lower murder rates:
Economic opportunity -> high correlation
Education access -> Strong correlation
Income inequality -> Direct negative correlation
Community investment -> Substantial preventive impact
Mental health support -> Significant preventife effect
