I observe a statistic
correlation between social class and , life expectancy, food habits, education grade, job chances. Or better, other observed and calclated that, and I just take note of it and refer to it.
A correlation is nothing you either beliueve or not. It is the result of a statistical calculation process. Formally, it is being done in a clearly defined methdological manner, it is neither random, nor totally arbitrary. It is not the result of believing something, nor do beliefs change it.
When a factor analysis gives you a highly significant result, for example, showing certain matches of features being interlinked, then that is so: there is a link. No matter what you believe.
Whether or not the one causally effects the other or another, third intermittend vartiable is envolved , is something different.
Again , we are not talking about opinion polls and hear-say or beliefs and ideas, but correlations, variance anylsis, factor analysis and the like. We are talking statistical methodology. Wanting to clean that off the table by just saying "I don'T buy it, I simply believe spomethign different", is a bit thin.
You better never take no drugs and medical substances the doctor had prescribed for you, because - ignoring betrayal and data forging for the moment - their licensing and permission for the market
all have been determined by such statistical methods, criterions and analysis.
Anyhow, I said what I have to say on the issue of links between social status and certain life parameters. I again refer to Gunnar Heihnsohn if you want scientific literature on demographic developement and its consequences, he is really no unknown name in this academic branch.