I promised to give an example of what I thought might be one approach to doing qualitative research on health inequality in an unfamiliar culture.
This came from merely a conversation I once had with someone from Hong Kong who insisted there was no such thing as social class there. Social class is a property of the industrial structure, and I don't know anything about industrial structure in Hong Kong so I could not argue with this. So if one wanted to do research on health inequality there, how to proceed?
I decided to try asking about social status. Using my understanding of caste systems (from undergraduate days) I zeroed in on some questions about co-mensality and intermarriage. I started with intermarriage and did not (as it turned out) have to go any further.
"Lets say you had a daughter and she told you she had fallen in love and wanted to marry", I proposed to my friend. "What sort of guy would you be hoping she would want to marry?"
"Well", he replied, "of course he would need to be Chinese" (my friend is Chinese).
I said "OK, but would there be anything else about the potential husband that you and your wife would really prefer?"
My friend thought for a few minutes. At last he said
"Oh! You mean colour! Yes, of course, I understand".
So here we have an example of a discovery about a social status hierarchy. I had previously had no idea whatever that, within the Chinese community in Hong Kong (which I had realised was of high status and pretty endogamous), there were additional gradations of colour.
But if I had not already had a lot of ideas at the back of my mind, ideas that arise from reading theories about social inequality of different types, I would not have (1) been aware of the difference between class and status (2) had any idea of how to ask questions that might elicit relevant responses for the discovery of status systems.
I later discovered, partly by talking to experts and partly by reading additional literature, that within the African-American population there is well known to be a so called "pigmentocracy" in which those of darker skin colour have a lower status. This can be shown to even have associations with health. That indicates to me that the colour hierarchy is a very profound and stable phenomenon that "gets under the skin".
Since becoming aware of this phenomenon I have learned about its effects on the lives of several friends. This is anecdotal stuff of course. But if I had not been taught about the criteria for caste membership, I would never have even begun to realise that "pigmentocracy" existed at all, certainly not in Hong Kong.
The point being that without asking questions informed by social theory, a basic feature of social inequality might have been totally missed by qualitative work.