Change the environment, change the person. It can be done en masse, though it's not as east. The reason the KIPP schools work, even though they take children randomly from extremely substandard environments, is that they completely control most aspects of the students lives. The school itself enforces a discipline that spreads like a contagion through the children from the start. In addition, they keep the kids there from 7 AM till 5-6 PM, before they go home, and for the most part keeps them in summer as well. So you can recreate this effect, but you need complete control from the top down, at least at the start.