Citing violent crime statistics as proof of a "cultural problem" without any regressors is not particularly helpful. What are the relevant demography-adjusted statistics? There are certainly some (edit: sub-)cultural aspects, but every culture has some aspects of the negative traits you cite (e.g. most people tend to disdain out-group achievement). These traits are often drastically accentuated by poverty. In the case of black Americans, doubly so by the compounding effects of high urbanization levels.