I have tried to elucidate and refine my question, but please feel free to edit it if I have not succeeded.
You will see from my editing history, that I am quite willing to edit questions to improve and clarify them. I would in this case too, but I honestly have no idea of what the claim means or how the question could be meaningfully answered.
I don't mean this as an attack; I hope this can help us resolve the issues and open the question.
I also need to be clear that - if it is just me who is confused, the question should be re-opened. My obtuseness shouldn't limit others. However, if I am confused, we can safely assume a lot of other readers will be too.
Here are some of my concerns:
What does it mean for a population to be "practical"? How can one measure that empirically?
What does it mean for a population to maintain an "empiricist and pragmatic disposition"? What does it mean for a population to maintain any disposition? How can one measure that empirically?
"an unwillingness to gauge their achievements in terms of principle." What does that mean? Why does anyone believe it is true?
You argue "a politically competent father does not imply the same for his son". Sure. Is a belief in that statement necessary for a class system to be sustained? I don't think so. Does it contradict empiricism? I can't see how; are we using the same definitions?
- The mixer taps issue requires every reader to sit through 3 minutes of video, only to be left confused about why it was mentioned. I would replace it with a brief description of the issue and how it relates to the question, but I really don't know what that relationship is. It just seems to be some part of UK culture that you find alien. Why not pick on their reluctance to move to metric? Or their dedication to dull sports?
You ask "how is it true", rather than "is it true"? [Note: Normally the phrase "Is it true" can be excised to simplify the title, but that's another issue.]
One way to resolve this confusion is to ask you a clarifying question: What sort of evidence would convince you that the answer was Yes, and what sort of evidence would convince you the answer was No?
Perhaps by seeing that, we can work out what the claim is.