> that causes racism. Elaborate?

to say that the reason people join gangs is cultural implies that it's a "bad culture" problem. the reality of why people join gangs is more complicated and includes overpolicing, economic deprivation, legacies of slavery and racism, and other factors. but if we say "it's just their culture" then we commit a fallacy that leads us to say "black people are doing this to themselves because of their bad qualities X,Y,Z", and we may also end up saying "black people are poor and disenfranchised for the same bad culture problems as lead them to form gangs". this is a classic fallacy, throughout human history, in which oppressed groups of people have their character impugned based on ignorant readings of the ways that they cope with and adapt to their situation, and thus are blamed for their own oppression