Justhadathought not sure how you took from that post that culture is the defining feature of class but okay then
Culture is the set of norms, values and social expectations that one lives with. 'Poverty' is often passed down through generations - as a result of culture and behaviour. I know that because I've lived in very materially impoverished circumstances myself ( as a single parent), and was born into a family that struggled, and who. still do, with money and material comfort.
However, what I did have benefit from was the valuing of education, learning and a sense of personal responsibility, and with that some degree of personal freedom from being defined exclusively by certain material or social conditions.
For example.....i would walk from one side of the city to the other - to visit friends, rather than take the bus...because I valued buying a decent loaf of wholemeal bread, over spending my meagre resources on the bus. I could eat fairly well with little money ( lentils, tinned toms, potatoes, are relatively cheap), and yet would see others in similar circumstances buying fast food, or overly expensive packaged food.....buying cigarettes.....
Culture is often what traps people in certain circumstances. That's probably to do with not having any feeling of personal power or responsibility......or that you could do something to change your circumstances or conditions of living.