Over at openDemocracy, there is a debate about John Rawls and the idea that inequality causes social and health problems.
If we accept for the sake of argument that Wilkinson&Pickett's thesis about equality is correct (which is a good bet as things stand - the criticisms have been pretty underwhelming), the next step is to look for a plausible causal pathway.
Kate Pickett suggested in a talk at the Green Party Conference that the phenomon might be rooted in the time we spent as tribes. Tribal economies are based on sharing - hunters hunt, gatherers gather, and in the evening, there is a communal meal. Equality, sharing even , comes naurally to us.
Let's take things a bit further. Imagine Tribe A rubbing along as above, who suddenly they find themselves dominated by a more powerful Tribe B, who live among them, albeit a little apart, with more and beter food, and in much larger tents.
Tribe A is going to be in a perpetual state of stress, secreting more cortisol among other things. This might provide a clue to the observed health effects, and at least some of the social effects.
Marmot's findings about the health of civil servants meshes in with this idea that it is the relative positions of rich and poor which is the operative factor. It's a relationship. We are part of a system.
So, whatever the correct interpretation may be of Rawls' idea, the weight of evidence points to the desirability of reducing inequality.
The point was made: "Rawls makes a moral proposition. No empirical data can prove it "wrong"." That reminds me of the don, who, on being told "The facts are otherwise" responded with "So much the worse for the facts".