Since I spent 20 years with black and other soldiers I am quite confident that color is not the issue; I vote for nurture, or the lack of it, in some cases.  

Of course, I was fortunate.  The ones I worked with and for had already self-selected for something besides being gang banging killers or drug-dealing drones or pimps when I knew them.  Whether they came from single mother families or had other disadvantages in their life, they accepted personal responsibility instead of expecting to be treated as 'victims of society' entitled to that which they hadn't earned.  

I saw a couple of pretty good altercations when a white guy accused a black guy of being a 'quota' or someone relying on  'affirmative action'!  Pride is something that is earned and protected.  Taking handouts just because you can is the exact opposite.  

The ones they left behind when my friends chose to make something of themselves are the ones who killed each other or wound up in prison or both.