Key to their argument is the idea that some cultures embrace bourgeois values more than others:

All cultures are not equal. Or at least they are not equal in preparing people to be productive in an advanced economy. The culture of the Plains Indians was designed for nomadic hunters, but is not suited to a First World, 21st-century environment. Nor are the single-parent, antisocial habits, prevalent among some working-class whites; the anti-“acting white” rap culture of inner-city blacks; the anti-assimilation ideas gaining ground among some Hispanic immigrants. These cultural orientations are not only incompatible with what an advanced free-market economy and a viable democracy require, they are also destructive of a sense of solidarity and reciprocity among Americans. If the bourgeois cultural script — which the upper-middle class still largely observes but now hesitates to preach — cannot be widely reinstated, things are likely to get worse for us all.